zbornikradova - Geodetski fakultet Sveučilišta u Zagrebu

Transcription

HRVATSKI GEODETSKI INSTITUT
ZBORNIK RADOVA
HRVATSKOG GEODETSKOG INSTITUTA
2001. - 2005.
Zagreb, prosinac 2005.
Nakladnik:
Mjesto izdavanja:
Godina izdavanja:
Naslov publikacije:
Broj stranica:
Za izdavatelja:
Urednik:
Tehnički urednici:
Tisak:
Naklada:
HRVATSKI GEODETSKI INSTITUT
10144 Zagreb, pp 19, Savska cesta 41/XVI
Telefon +385-1-6312400, telefax +385-1-6312410
E-pošta hgi@hgi.htnet.hr, Internet www.hgi.htnet.hr
Zagreb
2005.
Zbornik radova Hrvatskog geodetskog instituta 2001.-2005.
127
prof. dr. sc. Nevio Rožić
prof. dr. sc. Nevio Rožić
mr. sc. Ilija Grgić
Slavko Lemajić, dipl. ing. geod.
Sonja Marketić Pašić, dipl. iur.
Hrvatski geodetski institut
80 primjeraka
CIP - Katalogizacija u publikaciji Nacionalna i
sveučilišna knjižnica - Zagreb
UDK 528(497.5)(082)
ZBORNIK radova Hrvatskog geodetskog
instituta : 2001. - 2005. / <urednik Nevio Rožić>.
- Zagreb : Hrvatski geodetski institut, 2006.
Tekstovi na hrv. i engl. jeziku. - Kazalo.
ISBN 953-95318-0-2
1. Hrvatski geodetski institut (Zagreb)
I. Geodezija -- Hrvatska -- Zbornik
460113063
ISBN 953-95318-0-2
UVOD
Dokumentiranje i objavljivanje rezultata obavljenih stručnih, znanstvenih i
razvojnih zadaća jedan je od temeljnih uvjeta sustavnog obavljanja poslova, stavljanja
na raspolaganje postignutih rezultata i saznanja stručnoj i znanstvenoj javnosti, trajnog
bilježenja rezultata rada kao odraza trenutka vremena i prioriteta aktivnosti: pojedinaca,
timova i institucija (ustanova) u cjelini. Iz perspektive mladih, odnosno novih ustanova,
posebice ustanova s predznakom visokostručne, znanstvene i razvojne aktivnosti,
pisano dokumentiranje i publiciranje obavljenih radova, kako na internoj, tako i na
eksternoj razini, ima posebice velik značaj. Naime, publiciranje radova pridonosi
afirmirmaciji ustanove, izgradnji i stjecanju stručne i znanstvene vjerodostojnosti te
promoviranju djelatnosti, specijaliziranosti i djelokruga odgovornosti.
Tijekom prvog četverogodišnjeg ciklusa rada Hrvatskog geodetskog instituta, u
razdoblju 2001.-2005. godine, dokumentiranju i publiciranju rezultata radova posvećena
je primjerena pozornost. Pri tomu, posebno mjesto svakako imaju oni radovi
zaposlenika Instituta, timova i Instituta u cjelini koji su predstavljeni javnosti na
međunarodnim i domaćim skupovima (kongresi, simpoziji) te koji su ujedno otisnuti u
zbornicima radova tih skupova ili odgovararjućim znanstvenim i znanstveno-stručnim
časopisima. Pomenute radove, iako su tematski i sadržajno različiti, povezuju dvije
razvidne činjenice. Prije svega činjenica da su sadržajno i kvalitetom zadovoljili
procedure recenziranja, prezentiranja i objavljivanja na relevantnim instancama, a u
relativno složenim uvjetima osnivanja i rada Instituta u njegovom prvom
četverogodišnjem razdoblju rada, kada je primarna energija i fokus institutskih
stručnjaka, uz prilično ograničene resurse, primarno bila usmjerena prema ustroju,
razradi i definiranju stručnih i razvojnih procesa Instituta. Druga je činjenica definirana
izvrsnošću radova, jer su uz pridržavanje svih načela izrade i razrade znanstvenog i
znanstveno-stručnog sadržaja, korektno izrazili, uobličili i javnosti predočili rezultate
obavljenih radova.
U ovom je Zborniku sakupljen i objedinjen pretežan dio relevantnih radova
vezanih uz Institut, koji su objavljeni u razdoblju 2001.-2005. godine. Radovi su uvršteni
u Zbornik u njihovom izvornom sadržaju i jeziku publiciranja, bez dopunske recenzije,
uz minimalno (ipak neophodno) tehničko prilagođenje formatu tiska i estetsko uređenje
teksta. Za svaki je rad precizno i faktografski navedena publikacija u kojoj je izvorno
objavljen, odnosno znanstveni ili znanstveno-stručni skup na kojem je predstavljen.
Redosljed radova u Zborniku je određen sukladno vremenskom slijedu publiciranja.
Potrebno je naglasiti da pokretanje edicije Zbornika radova Hrvatskog
geodetskog instituta ima važnu svrhovitost. Ima svrhovitost objedinjavanja i očuvanja
rezultata rada stručnjaka Instituta, stvaranja trajne uporabne vrijednosti i referentnosti
objavljenog sadržaja, odnosno ima funkciju promicanja i afirmiranja Instituta u cjelini.
Čini se uputnim, što će svakako ovisiti o intenzitetu aktivnosti Instituta u narednom
razdoblju, priređivati Zbornik radova Hrvatskog geodetskog instituta bar u
četveregodišnjem vremenskom ciklusu. Također, kao primjeren kriterij uvrštenja radova
u Zbornik i nadalje je uputno zadržati kriterij prethodne publiciranosti radova u
meritornim znanstvenim ili znanstveno-stručnim časopisima, odnosno prezentiranosti
na relevantnim međunarodnim ili domaćim skupovima.
Zagreb, prosinac 2005.
Ravnatelj HGI
Prof. dr. sc. Nevio Rožić
INTRODUCTION
Documenting and publishing of the professional, scientific and development
tasks results done is one of the basic conditions for systematic dealing with jobs,
placing the achieved results and findings at disposal to professional and scientific
public, for permanent recording of the working results being the reflection of the
moment and the priority in the activities of individuals, teams and institutions as a
whole. From the perspective of the young, i.e. new institutions, especially those
characterized by highly professional, scientific and developmental activities, the written
documenting and publishing of the works done at internal as well as at the external
level has got a very large significance. Namely, the publishing of works makes great
contributions in promoting the institution, building and acquiring professional and
scientific credibility and promoting the activity, specialisation and the scope of
responsibility.
During the first four-year working cycle of the Croatian Geodetic Institute in the
period between 2001 and 2005, special attention has been paid to documenting and
publishing of the works. In this respect, special attention has been given to those works
of the employees in the Institutes, the teams and the whole Institute that were
presented to the public at international gatherings abroad and at home (congresses,
symposia), and that were printed in the proceedings of these gatherings or in adequate
scientific, and scientific-professional magazines. The above-mentioned works, although
thematically and contextually different, are connected by two obvious facts. First of all,
it is the fact that they have met the requests of review procedures, of the presentation
and publishing at relevant levels, and having in mind relatively complex conditions in
which the Institute was being founded and was working in its first four-year working
cycle, when the primary energy and attention of the Institute employees was first of all
focused toward constitution, elaboration and defining of professional and
developmental process of the Institute with pretty limited resources.
Almost all works relevant to the Institute and published in the period between
2001-2005 are gathered in these Proceedings. The works are introduced into the
Proceedings in their original form and in the original language of publishing, without any
additional reviewing, with minimal (really indispensable) technical adjustment to the
printing format and aesthetical text editing. There are precise and correct data given for
each work about the publication in which it had been originally published, i.e. the
scientific, or scientific and professional gathering at which it had been presented. The
order of the appearance of the works in the Proceedings has been determined in
accordance with the time they were published respectively.
It should be pointed out that the edition of the Proceedings of the Croatian
Geodetic Institute has been initiated with a very important purpose. The purpose is to
unite and keep the results the experts from the Institute have achieved, to create
permanent application value and reference of the published contents, i.e. to promote
and affirm the Institute on the whole. It seems advisable, and it will of course depend on
the intensity of the Institute's activity in the forthcoming period, to work on the
preparation of the Proceedings at least within the four-year cycle. It is also
recommendable to take the previous publishing of the works in competent scientific, or
scientific and professional magazines, i.e. their presentation at relevant international
gatherings abroad or at home as the criteria for their introduction into the Proceedings.
Zagreb, December 2005
Director of CGI
Prof. Dr. Sc. Nevio Rožić
SADRŽAJ
Nevio Rožić
…….7
Nevio Rožić
Croatian Geodetic Institute
…….9
Nevio Rožić
Accuracy of geometric levelling networks at the territory of Croatia
…...11
Željko Hećimović, Danko Markovinović
Stabilnost mjernog sustava Scintrex HGI-2 gravimetra
…...17
Nevio Rožić
Točnost visinske osnove geometrijskog nivelmana na teritoriju Republike Hrvatske
…...25
Željko Hećimović, Nevio Rožić, Tomislav Bašić, Danko Markovinović
Status of the Croatian First Order Gravity Network
…...33
Nevio Rožić
Strategy and System of Quality Control of the Official Geographic Data produced by
Private Companies in Croatia
…...41
Željko Bačić, Nevio Rožić
Cambridge Conference 2003 "National Mapping – Shaping the Future"
…...47
Nevio Rožić, Slavko Lemajić, Mladen Rapaić
Croatian-Norwegian GeoInformation Project
…...51
Slavko Lemajić, Nevio Rožić, Mladen Rapaić
Improvement of Quality Control System in Croatia
…...57
Stanislav Frangeš, Mladen Rapaić
Creating the toponymic database of the Republic of Croatia - Project Toponimis, as
sub-project of STOKIS
…...65
Ilija Grgić
Specifičnosti geodetske osnove u tunelogradnji
…...71
Nevio Rožić
Changes of benchmark heights being the consequence of introducing the new Croatian
height system
…...73
Željko Hećimović, Bojan Barišić, Ilija Grgić
Eeuropean vertical reference network (EUVN) considering Champ and Grace gravity
models
…...81
Mladen Rapaić, Stipica Pavičić, Slavko Lemajić
Topographic data production as basis for NSDI - Croatian example
…...91
Ilija Grgić, Slavko Lemajić, Bojan Barišić
Visinska kontrola geodetskih i kartografskih proizvoda u procesu topografske i
katastarske izmjere
….101
Slavko Lemajić, Višnja Miloš, Ilija Grgić
Kontrola kvalitete DOF-a u procesu katastarske izmjere
….107
Bojan Barišić, I. Vilibić, Ilija Grgić
Metodologija određivanja crte srednjih viših visokih voda
….113
Ilija Grgić, Bojan Barišić, Mihajla Liker
Status of the EUVN and EUVN_DA projects in Croatia
….119
Višnja Miloš
Digitalni ortofoto u Republici Hrvatskoj i u svijetu: norme i stanje u praksi
….125
HRVATSKI GEODETSKI INSTITUT*
Nevio Rožić
Od 1. ožujka 2000. godine u Republici Hrvatskoj se primjenjuje Zakon o državnoj izmjeri i
katastru nekretnina (Narodne novine 128/99), koji je donio Zastupnički dom Hrvatskog državnog sabora
na sjednici od 5. studenoga 1999. godine. Taj Zakon donosi brojne i suštinski važne odredbe koje
uređuju geodetsku djelatnost u Republici Hrvatskoj, a obuhvaćaju reguliranje kompleksnih područja
geodetskih poslova od državnog interesa, kao što su: državna izmjera, katastar nekretnina, registar
prostornih jedinica, katastar vodova, geodetski radovi za posebne potrebe, nadležnosti i obavljanje
poslova državne izmjere i katastra nekretnina, te ustrojstvo Državne geodetske uprave.
Jedna je od važnih odredbi i novina koje donosi ovaj Zakon osnivanje nove ustanove za trajno
obavljanje geodetske djelatnosti od interesa za Republiku Hrvatsku, pod nazivom Hrvatski geodetski
institut ili skraćeno HGI. U tom je smislu Zakon osnivački akt Instituta i u njemu su u poglavlju IV. točka 3,
sukladno Zakonu o ustanovama (Narodne novine 76/93), jasno precizirani elementi potrebni za njegovo
osnivanje. Tako je učinjen prvi i iznimno važan korak koji će u idućem razdoblju omogućiti ustrojavanje
Instituta i početak rada. Treba naglasiti i istaknuti veliku zaslugu svih sudionika koji su u postupku
predlaganja i donošenja Zakona omogućili osnivanje Instituta. Naime, konačno je uspješno realizirana
ideja koja je u geodetskoj javnosti Republike Hrvatske u različitim oblicima prisutna četrdesetak godina.
Gotovo da i nije potrebno podrobnije obrazlagati genezu, opravdane potrebe i razloge osnivanja Instituta.
Oni su i više nego razvidni s obzirom na stanje geodetskog naslijeđa Republike Hrvatske iz prethodnog
razdoblja, pojave i primjene suvremenih geodetskih i računalnih tehnologija i koncepcija obavljanja
geodetskih radova, preustroja cjelokupne geodetske djelatnosti na načelima tržišnih odnosa i
poduzetništva, preustroja ovlasti i tijela državne uprave nadležnih za obavljanje geodetskih poslova,
novih nastojanja i nove uloge geodezije u suvremeno orijentiranoj državi i društvu, nove pravne,
zakonske i pravilničke regulative i mnogo toga drugoga. U tom smislu Institut je krupna promjena u
organizaciji, ovlastima i obavljanju geodetske djelatnosti na državnoj razini i od državnog interesa. Institut
se pojavljuje kao novi geodetski subjekt i važna spona koja bi trebala u području vođenja, organiziranja i
obavljanja geodetskih radova na nov i drugačiji način povezati postojeće geodetske potencijale države.
Prije svega geodetsku operativu, koja se sastoji od niza kvalitetnih i uglednih geodetskih tvrtki ovlaštenih
za obavljanje geodetske djelatnosti, Državnu geodetsku upravu Republike Hrvatske i Geodetski fakultet
Sveučilišta u Zagrebu.
Nije na odmet podsjetiti i na prvu konkretnu inicijativu za osnivanje takve ustanove u Republici
Hrvatskoj. Naime, u razdoblju nakon II. svjetskog rata, a posebno nakon osnivanja samostalnoga
Geodetskog fakulteta 1962. godine pojavila se i jasno iskazala potreba osnivanja Geodetskog instituta.
Ona je bila na Fakultetu potaknuta potrebom izvođenja organiziranog i sustavnog
znanstvenoistraživačkog rada u suradnji s geodetskom praksom i potrebom rješavanja niza
visokostručnih geodetskih zadaća koje su se nametnule pred geodetsku djelatnost onoga doba.
Inicijativa za osnivanje Geodetskog instituta je na Fakultetu i formalizirana. Poprimila je konkretan oblik i
ugrađena je u opće akte Fakulteta iz 1964. i 1966. godine. Iako se organizacijski oblik tadašnjeg instituta
razlikovao od današnjeg, zanimljivo je iz ove perspektive podsjetiti na neke pojedinosti.
Statutom Geodetskog fakulteta iz 1964. godine donesena je odluka o osnivanju Geodetskog
instituta Geodetskog fakulteta (čl. 10. Statuta) sa sljedećim temeljnim zadaćama: organiziranje i
obavljanje znanstvenog rada te usavršavanje metoda rada u svim područjima geodezije, ispitivanje i
analiziranje geodetskih radova s obzirom na točnost, primijenjene metode i ekonomičnost, davanje
znanstvene podloge i usavršavanje geodetskih tehnoloških postupaka, suradnja s privrednim i drugim
organizacijama, odnosno znanstvenim ustanovama u zemlji i inozemstvu, objavljivanje rezultata
znanstvenog i stručnog rada, usavršavanje i izobrazba znanstvenog i stručnog podmlatka i dr. Sukladno
odredbama ondašnjeg Zakona o organizaciji naučnog rada, Geodetski je institut trebao djelovati kao
znanstvena ustanova, a upravljanje institutom trebalo je biti u ovlasti Savjeta Geodetskog fakulteta i
direktora kojeg postavlja Savjet. U tom su razdoblju za osnivanje Geodetskog instituta postojali kadrovski
uvjeti, kao i oprema za početak rada, dok su nedostajali prostor i financijska sredstva. Iako je osnivanje
instituta podržavala stručna praksa, do osnivanja na žalost nije došlo, bez obzira na visoku razinu
pripremljenosti. Konačno, početkom sedamdesetih godina, tj. 1973. godine ideja osnivanja instituta je
napuštena i nadomještena novim unutarnjim preustrojem Fakulteta utemeljenim na osnivanju Zavoda.
*
Objavljeno u Geodetskom listu 2000. godine (Rožić, N.: Hrvatski geodetski institut. Geodetski list, 2000,
4, 293-294).
-7-
Nakon ovoga kratkog podsjećanja potrebno je iznijeti temeljne i načelne odrednice na kojima
počiva osnivanje Instituta danas. Naime, sukladno odredbama Zakona, Hrvatski geodetski institut je
javna ustanova sa sjedištem u Zagrebu koja će trajno obavljati poslove državne izmjere i katastra
nekretnina koji su od interesa za Republiku Hrvatsku. Osnivač Instituta je Republika Hrvatska, a njezina
prava kao osnivača ostvarivat će Vlada Republike Hrvatske. Institut je neprofitabilna ustanova s javnošću
rada, koja neće obavljati svoju djelatnost radi stjecanja dobiti. Financiranje i sredstva za početak rada i
daljnji rad osigurana su državnim proračunom Republike Hrvatske. Dio potrebne geodetske i računalne
opreme Institutu će staviti na raspolaganje Državna geodetska uprava. Institut treba djelovati sukladno
Zakonu, Zakonu o ustanovama, vlastitim općim aktima i svim drugim zakonima i propisima koji uređuju
njegovu djelatnost. Rad Instituta nadzirat će Državna geodetska uprava, a djelatnost će biti planirana i
realizirana sukladno godišnjim programima rada. Ti programi će biti usklađeni s višegodišnjim
programima rada predloženima od Državne geodetske uprave i odobrenima od Hrvatskoga sabora i
Vlade Republike Hrvatske. Temeljna su tijela Instituta, sukladno Zakonu i Zakonu o ustanovama,
Upravno vijeće s 10 članova i ravnatelj, koje imenuje i razrješava Vlada Republike Hrvatske. U Institutu
bi trebalo raditi dvadeset djelatnika, a od toga broja petnaestak visoko kvalificiranih geodetskih
stručnjaka specijaliziranih u pojedinim užim područjima geodezije.
Djelatnost je Instituta u najširem smislu definirana poslovima državne izmjere i katastra
nekretnina. Međutim, u užem smislu, vrlo je precizno utvrđena čl. 44. Zakona i obuhvaća: vođenje
osnovnih geodetskih radova, ustrojavanje topografskih, kartografskih i katastarskih baza, vođenje
topografske izmjere, ustrojavanje i evidenciju zemljopisnih imena, vođenje izmjere i označavanja državne
granice, vođenje razvojno-istraživačkih projekata, rad na standardizaciji i normiranju geodetskih radova i
postupaka. Uz obavljanje visokostručnih geodetskih poslova Institut će posebnu pozornost posvetiti
razvojno-istraživačkoj i znanstvenoj problematici, koja je povezana s unapređenjem stručnog rada,
uvođenjem suvremene geodetske i računalne tehnologije te suvremenih standarada i postupaka
obavljanja geodetskih radova.
U tijeku su aktivnosti povezane s ustrojem Instituta sukladno zakonskim propisima. Prvi je korak
u tom smislu imenovanje privremenog ravnatelja Instituta odlukom Vlade Republike Hrvatske. U tijeku je
predlaganje i imenovanje članova Upravnog vijeća, izradba prijedloga Statuta Instituta i upis u sudski
registar ustanova. Navedene bi aktivnosti trebale biti obavljene u predstojećem razdoblju tako da će kao
pravni subjekt Institut početi djelovati i prije isteka ove kalendarske godine. Naravno, ustroj Instituta i
početak njegova operativnog rada povezan je i s nizom neriješenih zadaća, kao što su: nalaženje
prostora za rad, opremanje suvremenom geodetskom i računalnom opremom, definiranje unutarnjeg
ustrojstva sukladno Zakonom utvrđenoj djelatnosti, donošenje potrebnih općih akata, zapošljavanje
visokokvalificiranih geodetskih stručnjaka i dr.
Na kraju ovoga sažetog i načelnog prikaza o Hrvatskom geodetskom institutu važno je naglasiti
da će pri svom ustroju i preuzimanju Zakonom utvrđenih ovlasti svakako trebati veliku potporu svih
geodetskih subjekata Republike Hrvatske. Također, u obavljanju svoje djelatnosti krajnje će stručno,
odgovorno, konstruktivno i motivirajuće surađivati sa svim domaćim i inozemnim geodetskim
ustanovama, tvrtkama, organizacijama, tijelima i udrugama, prinoseći unapređenju, afirmaciji i napretku
hrvatske geodezije.
-8-
CROATIAN GEODETIC INSTITUTE*
Nevio Rožić
1. INTRODUCTION
After acquiring the independence and sovereignty at the beginning of the 90-ties there were
pretty significant and extensive activities initiated in the Republic of Croatia in the field of geodetic and
surveying works at the state level. The activities included reorganisation of state bodies and institutions
competent for carrying out geodetic and surveying activity of state interest, creating new law and
ordinance basis, evaluating and using the inherited geodetic basis of the former state (fundamental state
networks, geodetic datums, cartographic and geodetic documentation etc.) and also carrying out new
geodetic works at the state level.
One of very important activities in terms of modernising geodetic and surveying activity and its
organisation in accordance with the experiences and practice of other developed European countries is
the foundation of a separate and specialised institution intended for performing scientific and highly
professional geodetic activity. This new institution is Croatian Geodetic Institute (CGI). In the Republic of
Croatia there had never been such an institution. During the long period of time, from the end of II. World
War till the moment of Croatia becoming independent, the realization of professional geodetic and
surveying jobs had been always under the competence of Military and Geographic Institute of former
Yugoslavia.
The foundation of CGI as institution specialised for performing geodetic activity that is of interest
to the Republic of Croatia is defined by the Law of State Survey and Real Estate cadastre that was
passed by the House of Representatives of the Croatian State Parliament on 5th November 1999 and
has been applied since 1st March 2000. As this Law became operative, concrete activities were initiated
in connection with the formation and establishment of CGI and have been continuously performed ever
since. The bearer of these activities is the State Geodetic Administration (SGA) of the Republic of
Croatia.
For the first time in the Republic of Croatia administrative and normative jobs in the field of
geodesy will be separated from professional jobs. CGI will do the professional jobs and SGA will take
care of the administrative and normative jobs at the state level.
2. FOUNDATION AND FORMATION OF CGI
In accordance with the Law of State Survey and Real Estate Cadastre, CGI is formed as
specialised institution for carrying out scientific and highly professional geodetic works being of interest
for the Republic of Croatia, but without the rights to be profitable. The residence of CGI is in Zagreb, the
founder is the Government of the Republic of Croatia, and SGA is the bearer of CGI foundation activities.
SGA is also legally entitled to supervise its work. The work of CGI is regulated by the Law of State
Survey and Real Estate Cadastre, by the Law of Institutions and other positive laws and regulations of
the Republic of Croatia.
Within its activity CGI is to perform the following jobs:
- conduct fundamental geodetic works
- constitute topographic, cartographic and land registry databases
- conduct topographic survey
- constitute and keep geographic names register
- conduct survey and marking of state border
- conduct development and research projects
- standardisation of geodetic works and procedures.
CGI will be obligated to perform geodetic works and activity in accordance with the annual
working programs harmonised with the working programs of SGA, and to submit reports to the
Government of the Republic of Croatia about performed works. Manager of CGI and Managing Board
consisting of 10 members run the CGI. They are appointed by the Government of the Republic of
Croatia.
*
Predstavljeno na EUREF2001 simpoziju (Symposium of the IAG Subcommission for Europe – EUREF)
održanom u Dubrovniku 16.-18.5.2001. godine. Objavljeno u zborniku radova Simpozija (Rožić, N.:
Croatian Geodetic Institute. Mitteilungen des Bundesamtes für Kartographie und Geodäsie, Band 23,
EUREF Publication No. 10, Frankfurt am Main, 2002, 211-212).
-9-
At this moment it is possible to employ 20 people in CGI in accordance with financial possibilities
determined by the budget of the Republic of Croatia. They have to be highly qualified experts in the field
of geodesy and informatics. Special attention will be paid to additional education and specialisation of
these employees, especially in the field of applying recent geodetic technologies of gathering, processing
and analysing geodetic data.
At this moment there is a procedure going on connected with preparation of adequate regulative
and other normative acts of the CGI that should be passed so that the CGI could start functioning
normally during the year 2001 in accordance with the law and regulations of the Republic of Croatia.
3. CGI INTERNAL CONSTITUTION AND NEAR FUTURE ACTIVITIES
Internal constitution of the CGI is based on the planned type and volume of geodetic works that it
should perform. The constitution of four departments is planned:
- Department for mutual jobs
- Department for fundamental geodetic works
- Department for topographic survey and supervising
- Department for geoinformational systems and databases.
Very important phase in the foundation of CGI and in providing the conditions for it to start
operating will be the employment of experts, getting premises for its work, gathering geodetic equipment,
more precise defining of its internal constitution and initiation of direct work.
The need for the CGI to start working as soon as possible is intensified by very extensive and
demanding program of geodetic works at the state level that has been made by the SGA. The
implementation of this program, the "Program of state survey and real estate cadastre for the period from
2001 – 2005", will depend also on the activity and efficiency of the work done by the CGI.
There is also a need for information about the situation and experiences referring to the work,
organisation and constitution of similar institutions in other developed European countries.
4. CONCLUSION
In accordance with the intention to constitute CGI as modern and efficient institution that will
work successfully on solving the problems in geodetic activity and perform works of interest to the
Republic of Croatia it can be concluded that all types of assistance from similar European institutions are
welcome having in mind objective circumstances that the geodetic activity and the Republic of Croatia as
a whole have found themselves in at the moment.
REFERENCES
Official Newspaper: The law of State Survey and Real Estate Cadastre, No. 128, Zagreb, 1999.
- 10 -
ACCURACY OF GEOMETRIC LEVELLING NETWORKS
AT THE TERRITORY OF CROATIA*
Nevio Rožić
ABSTRACT
In the period between 1945 – 1990 there were numerous works of geometric levelling carried out
at the present territory of the Republic of Croatia. These works are the basis for the new height system of
the Republic of Croatia. The accuracy assessment of these works has been determined, with respect to
the measuring accuracy, as well as to the benchmark height accuracy in accordance with the new
definition of vertical datum and height system of the Republic of Croatia.
1. INTRODUCTION
At the territory of the Republic of Croatia the extensive works on general geometric levelling
were made in the period between 1945 and 1990. These are the following works: high accuracy levelling
(NVT), precise levelling (PN), city levelling (GN), technical levelling of higher accuracy (TNPT) and
technical levelling (TN). Within the scope of these works there were numerous levelling lines made and
extensive bench mark fields established that cover, mostly adequately, the entire territory of Croatia
pursuant to: geographic, traffic, economic and other characteristics of single areas of regions, and to
financial, technical, material and organisational circumstances stipulating their execution. Bench mark
fields and levelling lines are unified completely in a coherent system of state levelling network
established on the classic hierarchy principle, i.e. following the orders of accuracy.
The extensive works of general geometric levelling are well defined by the data contained in the
archives of the State Geodetic Administration of Croatia. Following various orders of accuracy there were
altogether 468 levelling lines made at the territory of Croatia encompassing about 23000 benchmarks.
Individual orders of levelling contain:
- 36 levelling lines of the First High Accuracy Levelling (INVT) and 45 levelling lines of the Second
High Accuracy Levelling (IINVT) – I. order
- 77 levelling lines of precise levelling – II.order
- 49 levelling lines of the city levelling – II. order
- 149 levelling lines of the technical levelling of higher accuracy – III. order
- 112 levelling lines of technical levelling – IV. order.
The above stated levelling works were made practically in the period between 1946 and 1973.
After the year 1973 there have been no systematic general levelling surveying. The original data, the
adjustment results, operational documentation (network sketches, levelling figure sketches, positional
bench mark descriptions, lists of heights) and other data are stored in the archives of the State Geodetic
Administration.
At the beginning of the nineties and after the Republic of Croatia has been recognised as an
independent and sovereign state, the work started on updating the inherited levelling networks and their
usage in new circumstances. These works, carried out during the nineties, did not include relevelling and
the renewal of benchmark fields due to high fieldwork costs (stabilisation, survey, etc.), but it is based on
maximum usage of the archive data considering economic, financial and organisational infractructure
(instruments, equipment, experts). Within the scope of these works a great amount of jobs has been
carried out:
- study on Updating the Levelling at the Territory of the Republic of Croatia has been made with
the assessment of the inherited situation in state levelling networks given in it, as well as the
proposal for improving this situation (Klak et al. 1992)
- the proposal of the Book of Ordinances about the Levelling Works has been made (Klak et al.
1993) that has been used as a normative and technical basis for carrying out the works on
levelling in general, i.e. making the revision of benchmark fields and of levelling networks
*
održanom u Ponta Delgadi, Azori, Portugal, 5.-9.6.2002. godine. Objavljeno u zborniku radova Simpozija
(Rožić, N.: Accuracy of geometric levelling networks at the terrritory of Croatia. Mitteilungen des
Bundesamtes für Kartographie und Geodäsie, Band 29, EUREF Publication No. 12, Frankfurt am Main,
2003, 336-340).
- 11 -
the extensive and systematic field revision of benchmark fields at the territory of the Republic of
Croatia has been made that are encompassed by the state levelling networks, and it has been
defined for every single bench mark in the field and the field as a whole, how far it has been
preserved or destroyed
- the operational documentation referring to benchmark fields has been systematically revised,
including: modernisation, updating in accordance with the results of field revision, production of
new levelling line and network maps and of benchmark positional descriptions
- extensive computing processing and measuring data adjustment of levelling has been made
along with their resystemising and with the reference to the new vertical datum and fundamental
levelling network, and new heights for all bench marks have been determined
- operational data for benchmark fields have started to be published in special publications in
edition of the State Geodetic Administration (Klak et al. 1994, Klak et al. 1998a, Rožić et al.
2001)
- three new levelling lines of height accuracy levelling have been designed and surveyed
(Koprivnica – Goričan, Virovitica – Terezino polje, Batina – Udvar) intended to connect the I.
Order levelling networks between the Republic Hungary and the Republic of Croatia (Klak et al.
1995, Klak et al. 1997a, Klak et al. 2000)
- geopotential and normal system of the Republic of Croatia has been defined and the height
system of the Republic of Croatia has been connected with the United European Levelling
Network – UELN (Klak et al. 1997, Klak et al. 1997b, Klak et al. 1998, Feil and Rožić 2000)
- the proposal has been made to have a new vertical datum introduced into official usage HRVD71 – Croatian Vertical Reference Datum 1971 (Feil and Rožić 2000a) that has been
evaluated by international advisers (Brockman et al. 2001)
- the Study on Renewal and Maintenance of the Height System of the Republic of Croatia has
been made accompanied by the analysis of the results obtained in the works carried out in the
period from 1992 – 2000 and by the proposals for the works to be executed inevitably in the
forthcoming period (Feil and Rožić 2001).
One of the most important and previously mentioned topics is processing and adjustment of
levelling networks intended for the determination of bench mark heights. The integral part of this
processing is also the determination of accuracy estimation criteria. Since the processing has been made
for the levelling lines at the entire territory of the Republic of Croatia, concrete indicators of levelling
network accuracy have been obtained.
-
2. ADJUSTMENT OF GEOMETRIC LEVELLING NETWORKS
The adjustment of geometric levelling lines and networks at the territory of the Republic of Croatia
was carried out gradually in the period between 1994 and 2000. It followed the field revision of benchmark
fields, and it was based on archive documentation kept in the State Geodetic Administration of the Republic
of Croatia and on the archives kept in few larger geodetic firms that had formerly executed some of these
works. Levelling networks were adjusted in accordance with the hierarchy principle, i.e. by lower order
networks referring to higher orders. As the reference for including the lower order networks (PN, GN, TNPT
and TN), a new vertical datum of the Republic of Croatia has been adopted, as well as IINVT network as the
fundamental levelling network (Rožić 2001), Fig. 1.
Applying the function model of indirect regular non-correlated measurements the adjustments of
networks have been made by the least squares method. Levelling networks and lines have been adjusted
individually in a single levelling figures of IINVT, Fig. 1. In this way the data processing has been divided into
a few phases. The results of data processing have been consequently published in a series of studies made
at the Faculty of Geodesy, University of Zagreb. The works have been executed in the following phases:
- the II. levelling loop IINVT – 1994
- I. levelling loop IINVT – 1995
- III. levelling loop IINVT – 1995
- VIII. levelling loop IINVT – 1996
- IV. levelling loop IINVT – the first part – 1996
- VI., XIV., XV. and XVI. levelling loop IINVT – 1997
- V. levelling loop IINVT – 1998
- IV. levelling loop IINVT – the second part – 1998
- III. and VIII. levelling loop IINVT - supplementations – 1999
- VIII. levelling loop IINVT - supplementation – 1999
- IX. levelling loop IINVT – 1999
- XII levelling loop IINVT – 1999
- VII. and XI. levelling loop IINVT and island levelling networks - 2000.
- 12 -
14
FR3053
Varaždin
15
16
FR3020
Zagreb
III
5
1
2
12
FR1029
Brajkovići
BV
MCXVII
Bakar
11
10
BP82
Rovinj
C46
Senj
21
9
I
IV
DCCLIII
Virovitica
A437
Novska
CP695
Kostajnica
20
37
VIII
C650
Okučani
44
41
18
BV11530
Daruvar
19
O362
Batina
17 C143
Pčelić
42
K274 43
Našice
38
FR3063
Strizivojna
22
MCCI
Ž.Lokva
CP317
Osijek
48
REPUBLIKA HRVATSKA
II. NIVELMAN VISOKE TOČNOSTI
23
V
26
0
10
20
30
40
50 km
Tumač znakova:
25
C162
Šibenik
31
čvorni reper
VI
BV14530
3
mareograf
nivelmanski vlak
MCCC
Split
PN167
30
br. nivel. vlaka
XIV
35
C346
Opuzen
63
Geodetski Fakultet
Sveučilišta u Zagrebu
XV
FR1098
XVI
C620
Dubrovnik
4
A496
62
60
Fig. 1. Levelling network IINVT at the territory of the Republic of Croatia
3. ACCURACY ESTIMATION RESULTS FOR GEOMETRIC LEVELLING
The accuracy of geometric levelling networks at the territory of the Republic of Croatia is given by
the accuracy criteria "a posterior", i.e. by reference probable measurement errors and probable errors of
network nodal benchmark heights determined on the basis of adjustment. They have been determined
according to single levelling orders and levelling figures of IINVT. Apart from the adjustment of the
fundamental levelling network, i.e. IINVT network (Rožić 1995), there have been altogether 127
adjustments of lower order geometric levelling networks being of various complexity (number of
measurements and unknowns). The adjustment has been executed for individual orders as follows:
- 16 precise levelling networks
- 58 city levelling networks
- 19 networks of technical levellings of increased accuracy
- 34 technical levelling networks.
The accuracy criteria "a posterior" are given in the table 1, divided in individual levelling figures of
IINVT and individual levelling orders. The table contains probable reference errors of measurement uo and
probable errors of nodal benchmark heights uH. There are always two probable errors of nodal benchmark
heights given. The probable error of nodal bench mark height that has got the lowest amount (min.- mH) and
the probable error of the bench mark height that has got the highest amount (max.- mH). The bench marks
referring to these probable errors have the highest, i.e. the lowest height accuracy. These probable errors
are indicators of height accuracies for all other benchmarks encompassed by the adjustment.
Table 1. Accuracy estimation for measurements and benchmark heights
IINVT
FIGURE
I.
uo
PN
min.uH
max.uH
mm / km
mm
mm
± 0,79
± 0,33
±11,77
uo
mm / km
GN
min.uH
max.uH
mm
mm
uo
TNPT
min.uH
max.uH
mm
mm
mm / km
uo
mm / km
TN
min.uH
max.uH
mm
mm
± 1,86
± 1,41
± 7,09
± 2,92
± 0,26
± 5,21
± 1,87
± 3,08
± 7,77
II.
± 4,59
± 6,04
±35,15
± 1,25
± 0,23
± 2,16
± 3,20
± 2,43
± 8,53
III.
± 2,56
± 1,61
±10,01
± 3,25
± 0,47
± 4,63
± 3,97
± 3,73
IV.
± 2,28
± 3,67
±10,23
± 2,10
± 1,03
± 2,07
± 6,55
±12,09
- 13 -
uo
mm / km
min.uH
max.uH
mm
mm
± 3,89
± 2,49
± 8,72
±14,25
± 6,09
± 1,21
±14,31
±12,09
± 6,73
± 6,59
±16,53
V.
± 2,14
± 2,44
± 9,20
± 2,31
± 0,50
± 2,37
VI.
± 2,03
± 1,14
± 6,06
± 3,03
± 0,31
± 3,86
± 8,18
± 3,57
± 3,48
± 6,50
VIII.
± 2,47
± 2,29
± 9,14
± 2,75
± 0,55
± 4,11
± 5,60
± 2,47
±11,29
IX.
± 1,15
± 1,24
± 9,59
± 4,84
± 0,57
± 4,73
VII.
XI.
XII.
± 1,15
± 1,24
± 9,59
XIV.
± 1,65
± 4,51
± 4,77
XV.
ISLAND
± 3,33
± 1,76
± 5,10
± 0,51
± 7,17
± 1,22
± 1,33
± 3,35
± 0,89
±19,20
± 2,27
± 5,41
± 5,52
± 6,95
± 4,10
± 7,83
± 3,33
± 4,48
± 7,51
± 8,05
± 4,62
±23,67
± 3,96
± 2,99
±12,03
± 1,47
± 5,55
± 6,35
±11,85
±16,41
±27,93
± 3,41
± 1,08
± 5,98
±25,92
On the basis of the data in the table 1 one can determine representative values of accuracy
criteria "a posterior" referring to single geometric levelling orders for the entire territory of the Republic of
Croatia. These accuracy criteria "a posterior" are given in the table 2.
Table 2. Accuracy estimation for measurements and benchmark heights
IINVT
uo
FIGURE
CROATIA
PN
uo
GN
uo
TNPT
uo
TN
uo
min.uH
max.uH
min.uH
max.uH
min.uH
max.uH
min.uH
max.uH
min.uH
max.uH
mm / km
mm
mm
mm / km
mm
mm
mm / km
mm
mm
mm / km
mm
mm
mm / km
mm
mm
± 0,79
± 0,33
±11,77
± 2,53
± 1,14
±35,15
± 2,70
± 0,23
± 7,17
± 3,42
± 2,43
±14,25
± 6,61
± 0,89
±27,93
4. CONCLUSIONS
On the basis of the accuracy estimation data given in the previous chapter, several conclusions can
be made. First of all, based on the table 2, it can be concluded that accuracies of measurement achieved at
the entire territory of the Republic of Croatia in all orders of levelling mostly meet the accuracy criteria
defined in advance. The measuring accuracy is also logically reduced from the higher order networks to
lower orders. The allowed values of probable reference measurement errors for single geometric levelling
orders are:
- high accuracy levelling, uo = ±1mm / km ,
-
precise and city levelling, uo = ±2mm / km ,
-
higher accuracy technical levelling, uo = ±5mm / km ,
- technical levelling, uo = ±8mm / km .
With regard to measuring accuracy, the precise and city levelling are partly exceptional, because
their accuracy is somewhat lower than it is allowed by the accuracy criteria.
The accuracy estimation data given in the table 1 show that there was no completely homogeneous
measurement accuracy achieved at the territory of the Republic of Croatia within the frame of single
geometric levelling orders. It is obvious that in some parts of its territory, i.e. in single IINVT figures, the
measuring accuracy is different within the frame of the same levelling orders, and sometimes even
considerably lower than allowed. The origins of this unhomogeneity are connected primarily with the
surveying quality, measuring procedures, instruments and other conditions. On the other hand, they are
partly the consequence of various time epochs that individual levelling orders belong to.
The height benchmark accuracy can be considered satisfactory and logical related to the
measuring accuracy. In the whole precise levelling, taking the entire state territory into account, the nodal
bench mark with the lowest height accuracy has the probable error of ± 35 mm, in the city and higher
accuracy technical levelling of ± 7mm, i.e. of ± 14 mm and in technical levelling of ± 28mm. A great
number of benchmarks has got a considerably higher height accuracy which can be very well seen from
the data in table 1. In this matter it should be taken into consideration that the accuracies of bench mark
heights are partly stipulated by the manner of network adjustment and by the fact that bench marks in
higher order levelling being fixed.
The achieved measuring accuracies and height accuracies of benchmarks are surprising to a
certain extent. Namely, taking into consideration the fact that the observation material was gathered in
long period of time (surveying in different time epochs), measured with different instruments, procedures
and accessories, and mostly collected in very modest material and technical conditions (the period
between 1945 and 1963), there has been a relatively satisfactory result obtained. Regardless of some
- 14 -
deficiencies contained by all means in the works of the geometric levelling, they still have adequate use
value, especially for practical purposes.
Anyway, at the moment the Republic of Croatia does not have higher quality levelling works at its
disposal that could be used, and the new systematic works on the renewal of bench mark fields and
updating of geometric levelling state networks has not yet started.
REFERENCES
Brockmann, E., Harsson, B.G., Ihde, J. (2001): Geodetic Reference System of the Republic of Croatia,
Consultants Final Report on Horizontal and Vertical Datum Definition, Map projection and Basic
Networks, Tehnical Report, June 2001.
Feil, L., Rožić, N. (2000): UELN geopotencijalni i normalni visinski sustav Republike Hrvatske, Geodetski
fakultet Sveučilišta u Zagrebu, Zagreb.
Feil, L., Rožić, N. (2000a): Prijedlog službenog visinskog datuma Republike Hrvatske, Geodetski fakultet
Sveučilišta u Zagrebu, Zagreb.
Feil, L., Rožić, N. (2001): Studija o obnovi i održavanju visinskog sustava Republike Hrvatske, Geodetski
Klak, S., Feil, L., Rožić, N. (1992): Studija o sređivanju geometrijskog nivelmana na području Republike
Hrvatske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Klak, S., Feil, L., Rožić, N. (1993): Pravilnik o radovima geometrijskog nivelmana – prijedlog, Geodetski
Klak, S., Feil, L., Rožić, N. (1994): Podaci o reperima - knjiga 1, Državna geodetska uprava Republike
Hrvatske, Zagreb, 1994.
Klak, S., Feil, L., Rožić, N. (1995): Povezivanje nivelmana visoke točnosti Republike Hrvatske, Republike
Slovenije i Republike Mađarske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Klak, S., Feil, L., Rožić, N. (1997): Ispitivanje mogućnosti određivanja geopotencijalnih visina, Geodetski
Klak, S., Feil, L., Rožić, N. (1997a): Povezivanje nivelmana visoke točnosti Republike Hrvatske i
Republike Mađarske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Klak, S., Feil, L., Rožić, N. (1997b): Precise levelling data of the Republic of Croatia for the United
European Levelling Network, Državna geodetska uprava Republike Hrvatske, Zagreb.
Klak, S., Feil, L., Rožić, N. (1998): Connecting of levelling of high accuracy between the Republic
Hungary and the Republic of Croatia in geopotential height system. Geodetski fakultet
Klak, S., Feil, L., Rožić, N. (1998a): Podaci o reperima - knjiga 2, Državna geodetska uprava Republike
Hrvatske, Zagreb.
Klak, S., Feil, L., Rožić, N. (2000): Povezivanje nivelmana visoke točnosti Republike Hrvatske i
Republike Mađarske - drugi dio, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Rožić N. (1995): Ispitivanje slučajnih i sistematskih pogrešaka u geometrijskom nivelmanu, Geodetski
fakultet Sveučilišta u Zagrebu, Zagreb, doktorska disertacija, Zagreb.
Rožić, N., Feil, L., Pavičić, S. (2001): Podaci o reperima - knjiga 3, Državna geodetska uprava Republike
Hrvatske, Zagreb.
Rožić, N. (2001): Fundamental levelling networks and height datums at the territory of the Republic of
Croatia, Acta Geodaetica et Geophysica Hungarica, Budapest, Vol. 36 (2), 231-243.
- 15 -
- 16 -
STABILNOST MJERNOG SUSTAVA SCINTREX HGI-2 GRAVIMETRA*
Željko Hećimović, Danko Markovinović
SAŽETAK
U radu je ispitivano ponašanje mjernog sustava Scintrex CG-3M, HGI-2 gravimetra. Hod je
glavna karakteristika stabilnosti mjernog sustava gravimetra. Ispitivanje je obavljeno na osnovi promjena
hoda u periodu od dva mjeseca, kontinuiranog mjerenja u periodu od devet dana i mjerenja u periodu od
jednog dana. Nakon uzimanja u obzir popravaka i korekcija u realnom vremenu preostali hod je sveden
-7
-2
na 1·10 ms . Na tako dobiven signal primijenjena je wavelet analiza i to Coifmanov wavelet petog reda.
Izvršena je multirezolucijska analiza signala do trećeg nivoa. Stabilnost mjernog sustava gravimetra je
analizirana s obzirom na frekvencije i amplitude aproksimacije i detalja signala mjerenja. Za rezidualna
polja detalja dani su osnovni pokazatelji statističke varijabilnosti.
KLJUČNE RIJEČI
hod gravimetra, wavelet analiza, multirezolucijska analiza, aproksimacija, detalj
ABSTRACT
In this work is behavior of Scintrex CG-3M, HGI-2 gravimeter analyzed. Drift is the main
characteristic of stability of gravimeter measurement system. Analysis are made considering drift
changes in period of two months, continuous measurements of nine days and measurements of one day.
-7
-2
Remaining daily drift is after using real time corrections 1·10 ms . Wavelet analysis is applied on oneday measurements. Signal is analyzed with Coifman wavelet of the fifth order. Multiresolutin
decomposition is developed to the third level. Stability of gravimeter measurement system is analyzed
considering frequencies and amplitudes of approximation and details. The main parameters of statistical
variability of details are presented.
KEYWORDS
drift, wavelet analysis, multiresolution analysis, approximation, detail
1. UVOD
-8
-2
Scintrex CG-3M relativni gravimetar ima rezoluciju očitanja 10 ms . Da bi mjerili tako fine
vrijednosti razlika ubrzanja sile teže, promjene položaja mjerne mase gravimetra se moraju odrediti na
-11
10 m, što je promjer atoma. Tako veliki zahtjev na mjerni sustav pretvara gravimetar u prijenosni mjerni
laboratorij kod kojeg moramo voditi brigu i o najmanjim varijabilnim utjecajima koji se javljaju tijekom
mjerenja. Stabilnost mjernog sustava kao jedna od osnovnih karakteristika gravimetra je karakterizirana
njegovim hodom.
Prije provođenja mjerenja CG-3M gravimetar treba proći niz procedura da bi bio spreman za rad.
Rad HGI-2 gravimetra je redovito praćen (Hećimović 2002) i slijedeće procedure su provedene nad njim:
1) temperaturna kompenzacija,
2) određivanje hoda gravimetara i podešavanje sata hoda gravimetara,
3) određivanje nule senzora nagiba gravimetra,
4) određivanje osjetljivosti senzora nagiba gravimetra.
Mjerenja gravimetrom su opterećena vremenskim utjecajima koji su nepoželjni u signalu
mjerenja. Scintrex CG-3M gravimetri imaju mogućnost korigiranja mjerenja u realnom vremenu za
temperaturu mjernog senzora, a priori hod gravimetra, promjenu nagiba gravimetra, Zemljine plimne
valove i konstantu gravimetra. Osim toga Scintrex CG-3M gravimetar ima mogućnost izbacivanja grubih
mjerenja i primjenu seizmičkog filtra koji otklanja ili umanjuje mikro seizmičke utjecaje (Scintrex 1998).
*
Predstavljeno na Znanstveno-stručnom simpoziju u povodu 40. godišnjice samostalnog djelovanja
Geodetskog fakulteta Sveučilišta u Zagrebu, održanom u Zagrebu 26.9.2002. godine. Objavljeno u
Zborniku radova Simpozija (Hećimović, Ž., Markovinović, D.: Stabilnost mjernog sustava Scintrex HGI-2
gravimetra. Zbornik radova znanstveno-stručnog simpozija povodom 40. godišnjice samostalnog
djelovanja Geodetskog fakulteta Sveučilišta u Zagrebu, Geodetski fakultet, Zagreb, 2002).
- 17 -
2. STABILNOST MJERNOG SUSTAVA GRAVIMETRA
Hod gravimetra je promjena nule mjernog sustava s vremenom i jedna je od osnovnih
karakteristika stabilnosti mjernog sustava (Torge 1989). Na osnovi stabilnosti mjernog sustava
zaključujemo kako često moramo ponavljati mjerenja na referentnoj točci da bi mogli pouzdano odrediti
hod na temelju diskretnih mjerenja. Za novije instrumente je promjena hoda s vremenom veća, a sa
starenjem mjerni sustav postaje stabilniji, a hod pravilniji. Prvo određivanje hoda HGI-2 gravimetra
izvršeno je u tvrtki Scintrex i iznosio je 2,12 mGal/dan. Stabilnost mjernog sustava HGI-2 gravimetra je
ispitivana na temelju promjena hoda u periodu nešto kraćem od dva mjeseca, na temelju kontinuiranih
mjerenja od devet dana i na osnovi mjerenja u intervalu od 24 sata.
Nakon provedenih prethodno navedenih procedura i koristeći navedene korekcije signala
mjerenja u realnom vremenu dobiveni su mjerni signali koji su korišteni u ovoj analizi. Naknadnom
obradom i analizom podataka mjerenja mogu se dobiti bolji rezultati jer se mjerenja mogu naknadno
osloboditi utjecaja varijacije tlaka zraka, loading efekta, Chandler Wobble efekta, dugoperiodičnih i
godišnjih Zemljinih plimnih valova, Zemljinih plimnih valova s obzirom na krutu i elastičnu Zemlju,
utjecaja varijacija podzemnih voda, mikro seizmike, tektonike ploča, lokalnog premještanja masa,
postglacijalnog vertikalnog uzdizanja, i dr.
-7
-2
Na sl. 1 su prikazana mjerenja za period od 24 sata. Očitanja variraju u rasponu od 2,9·10 ms ,
-7
a preostali dnevni hod je 1·10
-2
ms . Prema propisima za državni premjer gravimetrijske mreže
-7
-2
Njemačke promjena signala gravimetra koji se koristi mora biti u području 1·10 ms . Taj kriterij se
odnosi na naknadno obrađeni signal, a ne na signal dobiven u realnom vremenu koji je ovdje prikazan.
Naknadnom obradom bi mogli poboljšati signal prikazan na sl. 1, ali u tom bi slučaju imali lošiji uvid u
stabilnost mjernog sustava gravimetra. Signal prikazan na sl. 1 će biti detaljno analiziran u poglavlju 4.
Na sli. 2 su prikazana kontinuirana mjerenja gravimetrom HGI-2 u periodu od devet dana. Kao
što se sa slike vidi dominira negativan paraboličan preostali hod gravimetra. U tablici 1 su prikazane
promjene hoda za intervale od 24 sata.
Slika 1. Očitanja gravimetra za interval mjerenja
od jedan dan
Slika 2. Očitanja gravimetra za interval mjerenja
od devet dana.
Tablica 1. Preostali hod u periodima po 24 sata
za mjerenja prikazana na slici 2.
Na osnovi podataka u tablici 1 uočava se povećavanje preostalog hoda u prvom danu, a u
sljedećim danima dolazi do nelinearnog smanjivanja hoda. Treba naglasiti da je promatrani signal
dobiven u realnom vremenu, a on se naknadnom obradom može poboljšati.
- 18 -
Da bi dobili cjelovitiji uvid u ponašanje mjernog sustava HGI-2 gravimetra periodično je
određivan hod (Hećimović 2002). Glavni rezultati su dani u tablici 2. Za prva tri određivanja je za a priori
dnevni hod korištena vrijednost 2,12 mGal/dan, a za daljnje vrijednosti je za a priori vrijednost hoda
korištena prethodno određena vrijednost.
Tablica 2. Pregled hoda gravimetra HGI-2.
Iz tablice 2 se vidi da dominira smanjivanje vrijednosti hoda. Na slici 3 su grafički prikazane
vrijednosti iz tablice 2 po danima od prvog određivanja hoda, gdje se jasno uočava smanjenje vrijednosti
hoda.
Slika 3. Promjena hoda gravimetra HGI-2 po danima.
Na osnovi izloženog višednevnog kontinuiranog mjerenja i periodičnog određivanja hoda uočava
se isti proces opuštanja mjernog sustava gravimetra. Razlog ne linearnom hodu u dužim mjerenjima je
najvjerojatnije mirovanje instrumenta i za očekivati je da će s vremenom doći do većeg stupnja stabilnosti
mjernog sustava i hoda. Naravno, hod će uvijek biti prisutan zbog promjena fizikalnih svojstava mjernog
sustava s vremenom. Period u kojem su izvršena mjerenja za ovu analizu je nešto manje od dva
mjeseca. To je kratko vremensko razdoblje za izvršiti dugoperiodičnu analizu stabilnosti mjernog sustava
gravimetra, naročito jer se radi o početku praćenja stabilnosti mjernog sustava HGI-2 gravimetra. Prema
propisima za državni premjer gravimetrijske mreže Njemačke hod gravimetara koji se primjenjuju za
premjer državne mreže treba biti praćen najmanje šest mjeseci.
Da bi dobili bolji uvid u ponašanje mjernog sustava gravimetra provest ćemo naknadnu analizu
-7
-2
signala mjerenja. Područje interesa naknadne analize je 1·10 ms u kojem se kriju utjecaji preostalih
signala instrumenta (nagiba instrumenta, temperaturne kompenzacije i temperaturnih šokova,
magnetizma, variranja napona, mehaničkih šokova) i preostali, prethodno nabrojani, utjecaji na signal
ubrzanja sile teže. U naknadnoj obradi je primijenjena wavelet analiza na signal dnevnog mjerenja
prikazanog na slici 1.
3. WAVELET ANALIZA
Wavelet (valići) analiza je relativno novi dio matematike koji se još intenzivno razvija. Wavelet se
prvi put spominje 1909. godine u radu Alferda Haara, a intenzivno se počinje razvijati u matematičkim
krugovima osamdesetih godina prošlog stoljeća. Zbog mogućnosti koje pruža, wavelet analiza se sve
više primjenjuje u rješavanju znanstvenih i stručnih problema. Wavelet analizom otvoreni su novi pristupi
matematičkoj percepciji realnosti. Ona otvara nove mogućnosti filtriranja signala, rješavanja parcijalnih
diferencijalnih jednadžbi, analize podataka, omogućuje jednostavnu primjenu multirezolucijske analize i
dr. Wavelet analiza nalazi sve više svoju primjenu i u geodeziji. Neki od primjera praktične primjene
waveleta u geodeziji su otkrivanje prekida GPS signala, prikaz digitalnog modela reljefa,
multirezolucijska analiza polja ubrzanja sile teže, primjena pri određivanju dužine dana (Schmidt i Schuh
1999), analiza i prikaz globalnog geopotencijalnog modela (Schmidt i dr. 2000). Od posebnog interesa za
analizu i modeliranje geodetskih podataka je područje primjene sfernih waveleta (Schmidt 2001).
Ovdje je dan kratak osvrt na wavelet analizu. Više o wavelet analizi se može naći u Antoniadis i
Oppenheim (1995), Resnikoff i Wells (1998), Torrence i Compo (1998). Wavelet analiza je proširenje
Fourierove analize, u kojoj operacija diskretne transformacije ima jednu od vodećih uloga. Kao i brza
Fourierova transformacija (Fast Fourier Transformation, FFT) diskretna wavelet transformacija (DWT) je
linearna operacija. Jedna od glavnih razlika između FFT i DWT je u tome što FFT koristi sinus i kosinus
funkcije kao funkcije baze u novoj domeni u koju se funkcija preslikava, a kod DWT funkcije baze su
- 19 -
složenije ali pružaju veće mogućnosti analiziranja. Za funkcije bazisa u wavelet analizi može se izabrati
beskonačno mnogo funkcija, ali samo neke omogućuju lokalizaciju u vremenu, što sinus i kosinus
funkcije ne omogućuju. Osim lokalizacije u vremenu, funkcija baze mora omogućavati i lokalizaciju
frekvencije, odnosno skale, što kod FTT-a osiguravaju sinus i kosinus funkcije. Za razliku od Fourierove
analize koja koristi vrijeme i frekvenciju kao osnovu predstavljanja signala, wavelet analiza koristi
frekvenciju i skalu. Mogućnost lokalizacije frekvencije je bitna prednost wavelet analize u odnosu na
Fourierovu. Zbog mogućnosti vremenske lokalizacije promatrane frekvencije wavelet analizom je
moguće obrađivati i ne stacionarne signale, što nije slučaj kod metode FFT-a.
U wavelet analizi centralnu ulogu ima wavelet funkcija, često nazivana "mother" wavelet, i
funkcija skaliranja, ako postoji. Wavelet funkcije možemo podijeliti u familije: osnovne wavelete,
regularne u beskonačnosti, ortogonalne i biortogonalne. Wavelet funkcije su dobivene na osnovi početne
osnovne funkcije primjenom dilatacije (rastezanje) i translacije (Antoniadis i Oppenheim 1995).
Generalno je wavelet funkcija kompleksna i vezana je uz skup kompleksnih brojeva Z. U ovom radu su
od posebnog interesa wavelet funkcije s ortonormalnom bazom. Pri tome za funkciju ψ, familija (ibid.),
2
2
definira ortonormiranu bazu u realnoj domeni L (R). Aproksimacija od L (R) se može definirati pomoću
2
zatvorenih podprostora Vj, j œ Z od L (R). Ortonormirani bazis od Vj je definiran familijom {φj,k : k œ Z} gdje
je
razvučen i translatiran oblik funkcije skaliranja. Multirezolucijska analiza definira ortogonalno rastavljanje
2
L (R). Ako definiramo Wj kao ortogonalni komplement od Vj u Vj+1, dobivamo novu sekvencu {Wj : j œ Z}
zatvorenih međusobno ortogonalnih podprostora. Pri tome je svaki Wj dilatacija od W0 i njihova suma je
2
jednaka L (R). Tada familija
formira ortonormiranu bazu svakog prostora detalja Wj. Ako je multirezolucijska analiza regularna tada
wavelet ψ ima momente jednake nuli do reda r, tj.
Prednost većeg broja momenata jednakih nuli za ψ je da su wavelet koeficijenti finije skale
jednaki nuli na dijelovima gdje je funkcija glatka. Ali povećanjem broja momenata jednakih nuli se gubi
na lokalnoj karakteristici analize te broj momenata jednakih nuli ne može rasti u beskonačnost već do
broja koji dopuštaju lokalne karakteristike signala. Moguće je konstruirati ortogonalni wavelet tako da
funkcija skaliranja φ ima N-1 momenata jednakih nuli, tj. da zadovoljava
Wavelet koji zadovoljava gornje uvijete je konstruirala matematičarka Ingrid Daubechies i nazvan
je Coifmanov wavelet po Ronaldu Coifmanu na čiji prijedlog je konstruiran (Antoniadis i Oppenheim
1995).
Wavelet analizom izvodimo dekompoziciju signala na dva signala: aproksimaciju i detalj. Signal
aproksimacije zadržava glavninu energije početnog signala ali je šum reduciran, a detalj sadrži preostali
dio viših frekvencija. Dekompozicija se može računati u više nivo, te za svaki nivo dobivamo
aproksimaciju i detalj na osnovi signala iz prethodnog nivoa. Analizu signala na više nivoa u raznim
rezolucijama nazivamo multirezolucijska analiza. Teoretski se postupak grananja može provesti u
beskonačnost, ali se prilikom praktičnog računanja ograničavamo do nivoa koji sadrži korisne
informacije.
Prilikom provođenja wavelet analize računamo koeficijente C(a,b) za signal s(t) na temelju
wavelet funkcije ψ pomoću izraza (ibid.)
- 20 -
j
j
2
gdje a = 2 definira promjenu skale, a b=k2 translaciju uz uvjet j, k œ Z . Detalj za nivo j dobivamo po
izrazu
Aproksimaciju možemo definirati kao grubi dio detalja
a rekonstrukciju signala možemo dobiti po izrazu
Aproksimacije na nivoima J-1 i J možemo povezati izrazom
4. WAVELET ANALIZA MJERNOG SIGNALA GRAVIMETRA
U ovom radu je zbog svojih osobina pri obradi signala gravimetra korišten Coifletov wavelet
petog reda iz familije ortogonalnih waveleta. Glavni predstavnici ove familije waveleta su Daubechiesov,
Symletov i Coiflet wavelet. Neke od glavnih osobina Coiflet waveleta petog reda su ortogonalnost
analize, postojanje funkcije skaliranja, mogućnost kontinuirane i diskretne wavelet transformacije, te
približna simetričnost. Coifletova wavelet funkcija ψ ima 2N momenata jednaka nuli, a funkcija skaliranja
φ ima 2N-1 momenata jednaka nuli (Resnikoff i Wells 1998). Coifmanov wavelet je zadan u numeričkom
obliku i prikazan je na slici 4, a na slici 5 prikazana je pridružena funkcija skaliranja.
Slika 4. Coifmanov wavelet petog reda
Slika 5. Funkcija skaliranja za Coifmanov
wavelet 5 reda.
Do kojeg nivoa možemo provesti multirezolucijsku dekompoziciju ovisi o prirodi signala. U ovom
radu je multirezolucijska dekompozicija provedena do trećeg nivoa, što je prikazano na slici 6.
Slika 6. Wavelet multirezolucijsko grananje.
Multirezolucijska dekompozicija signala sa slike 1 je prikazana na slici 7. Na apcisnoj osi su
nanijete epohe mjerenja koje su trajale 60 sekundi.
Sa slike 7 se uočava da se povećavanjem nivoa dekompozicije smanjuje količina informacija u
preostalom detalju. Aproksimacija preuzima trend i dio vezan uz glavnu energiju signala. Aproksimacija
je oslobođena visoko frekventnog dijela te se promjene signala s kraćim periodama i poludnevnim
- 21 -
periodama jasnije uočavaju. Kraće periode imaju trajanje od 10 do 30 minuta. One su nepravilne i imaju
amplitude manje od 0,01 mGal. One su najvjerojatnije prouzrokovane duže periodičkim mikroseizmičkim
utjecajem na gravimetar. Promjene signala s poludnevnim periodama imaju uglačan karakter. Njihov
uzrok može biti instrumentalni ili ostatak utjecaja signala koji djeluju na ubrzanje sile teže, a nisu
kompenzirani u realnom vremenu.
Slika 7. Aproksimacija A3 i detalji D1, D2 i D3.
Detalji nam daju uvid u kratko periodični dio signala i njima možemo analizirati finije strukture
signala koje imaju karakteristike šuma. Trajanje kratko periodičnih promjena za detalj D1 je uglavnom na
nivou promjene za jednu epohu mjerenja od 60 sekundi, za detalj D2 četiri epohe i za D3 nešto manje od
deset epoha. Raspon amplituda za detalj D1 iznosi 0,017 mGal, za D2 0,015 mGal i za D3 0,009 mGal.
Smanjivanje raspona ostatka informacija u detalju s povećanjem dekompozicijskog nivoa je 0,002 mGala
između prvog i drugog nivoa i 0,006 mGal između drugog i trećeg nivoa. Pokazatelji statističke
varijabilnosti za detalje su prikazani na slici 8 i tablici 3.
Tablica 3. Osnovni pokazatelji statističke varijabilnosti detalja D1, D2 i D3.
Slika 8. Histogrami detalja D1, D2, D3.
- 22 -
Iz pokazatelja statističke varijabilnosti signala (tablica 3) vidi se da su signali detalja centrirani.
Za detalje D1, D2 i D3 su izračunani spektri gustoće snage detalja (v. sliku 9).
Slika 9. Spektri gustoće snage detalja D1, D2 i D3.
Na osnovi spektara gustoće snage uočljivo je da dolazi do smanjenje frekvencija spektra detalja
s povećanjem multirezolucijsko dekompozicijskog nivoa.
5. ZAKLJUČAK
-7
-2
Preostali hod gravimetra HGI-2 je korekcijama u realnom vremenu sveden na 1·10 ms , ali
mjerni sustav gravimetra pokazuje opuštanje što se uočava u kontinuiranim višednevnim mjerenjima i
kod određivanja hoda u periodu od nešto manje od dva mjeseca. Razlog je najvjerojatnije višegodišnje
mirovanje gravimetra. Za očekivati je da će vremenom doći do višeg stupnja stabilizacije mjernog
sustava gravimetra.
Primjenom wavelet analize je dobivena aproksimacija na trećem multirezolucijskom nivou u kojoj
se uočavaju promjene mjernog sustava u kraćim periodama u trajanju od 10 do 30 minuta i poludnevnim
periodama. Promjene u kraćim periodama imaju amplitude manje od 0,01 mGal i najvjerojatnije su
prouzrokovane duže periodičkim mikroseizmičkim utjecajem na gravimetar, dok uzrok promjena s
poludnevnim periodama može biti instrumentalni ili ostatak utjecaja prirodnih signala koji djeluju na
ubrzanje sile teže, a nisu kompenzirani u realnom vremenu. Raspon amplituda za detalj D1 iznosi 0,017
mGal, za D2 iznosi 0,015 mGal i za D3 iznosi 0,009 mGal. Područje frekvencija se u spektrima gustoće
snage za detalje smanjuje s povećavanjem nivoa multirezolucijske dekompozicije.
Ovo je početak praćenja stabilnosti mjernog sustava gravimetra HGI-2. Stvoreni su uvjeti za
njegovo detaljno praćenje i analizu, a to je neophodno da bi se rezultati mjerenja mogli pravilno
interpretirati.
LITERATURA
Antoniadis, A., G. Oppenheim (Ed.) (1995): Wavelet and Statistics. Springer Verlag, New York, Berlin,
Heidelberg.
Hećimović, Ž. (2002): Izvještaj o praćenju rada HGI-2 gravimetra. Hrvatski geodetski institut.
Resnikoff, H. L., R. O. Wells (1998): Wavelet Analysis. Springer, New York, Berlin, Heidelberg.
Schmidt, M., H. Schuh (1999): Frequency-Dependent Phaes Lags between LOD- and AAM- Variations
Detected by Wavelet Analysis. www.dgfi.badw.de.
Schmidt, M., W. Martinez, J. Florez (2000): General Scheme for the Computation of Regional Geoid
Undulations Using Spherical Wavelets. www.dgfi.badw.de.
Schmidt, M.(2001): Computation of Geoid Undulations from Gravity Anomalies by Means of Scintrex
(1998): CG-3/3M Gravity meter, User's Guide, 1998.
Spherical Wavelets. Poster on the IAG 2001 Scientific Assembly, 2. - 8.9.2001. Budapest.
Torge, W. (1989): Gravuimetry. Walter de Gruyter, Berlin, New York.
Torrence, C., G.P. Compo (1998): A Practical Guide to Wavelet Analysis. Bulletin of the American
Meteorological Society, 61-78.
- 23 -
- 24 -
TOČNOST VISINSKE OSNOVE GEOMETRIJSKOG NIVELMANA
NA TERITORIJU REPUBLIKE HRVATSKE*
Nevio Rožić
SAŽETAK
U razdoblju 1945.–1990. godine izvedeni su na današnjem teritoriju Republike Hrvatske brojni
radovi geometrijskih nivelmana različitih redova točnosti. Ti su radovi osnova novog visinskog sustava
Republike Hrvatske. U ovom se radu navode podaci i analize ocjene točnosti tih radova u pogledu
točnosti mjerenja i visinske točnosti repera, u suglasju s novom definicijom visinskog datuma i visinskog
sustava Republike Hrvatske predloženog za uvođenje u službenu uporabu.
KLJUČNE RIJEČI
geometrijski nivelman, nivelmanske mreže, točnost mjerenja
ABSTRACT
In the period from 1945 till 1990 significant and extensive works on the geometric levelling of all
orders were carried out at the territory of the Republic of Croatia. This works serve as basis of new
height system of the Republic of Croatia. In this paper accuracy data and accuracy analysis of this works
are presented in wiew of measurement accuracy and bench-mark height accuracy accordingly with new
definition of height datum and height system of the Republic of Croatia proposed for official usage.
KEYWORDS
geometric levelling, levelling networks, measurement accuracy
1. UVOD
Na teritoriju Republike Hrvatske izvedeni su u razdoblju od 1945. do 1990. godine obimni radovi
generalnog geometrijskog nivelmana. To su radovi: nivelmana visoke točnosti (NVT), preciznog
nivelmana (PN), gradskog nivelmana (GN), tehničkog nivelmana povećane točnosti (TNPT) i tehničkog
nivelmana (TN). U sklopu tih radova izvedeni su brojni nivelmanski vlakovi i ustrojena su obimna polja
repera. Dio je vlakova izveden u obliku klasičnih linijskih vlakova, dok je dio vlakova izveden u obliku
većih i složenijih nivelmanskih mreža, posebno gradskih i tehničkih nivelmana. Tim je vlakovima,
uglavnom primjereno, pokriven cjelokupan teritorij Hrvatske sukladno: geografskim, prometnim,
ekonomskim i drugim karakteristikama pojedinih područja ili regionalnih cjelina te financijskim,
tehnološkim, materijalnim i organizacijskim prilikama koje su uvjetovale njihovu izvedbu. Polja repera i
nivelmanski vlakovi koji ih povezuju, objedinjeni su u cjeloviti sustav državne nivelmanske mreže
geometrijskog nivelmana ustrojene na klasičnom hijerarhijskom načelu, tj. po redovima točnosti. Polja
repera čine materijalnu osnovu visinskog sustava koji je na teritoriju Hrvatske služio i još uvijek služi za
rješavanje stručnih i znanstvenih geodetskih zadaća.
Obimnost radova generalnog geometrijskog nivelmana dobro definiraju podaci sadržani u arhivu
Državne geodetske uprave Republike Hrvatske. U različitim redovima točnosti izvedeno je na teritoriju
Hrvatske ukupno 468 nivelmanskih vlakova, kojima je obuhvaćeno približno 23000 repera. Pojedinim
redovima geometrijskog nivelmana pripada:
- 36 nivelmanskih vlakova Prvog nivelmana visoke točnosti (INVT) i 45 nivelmanskih vlakova
Drugog nivelmana visoke točnosti (IINVT) – I. red,
- 77 nivelmanskih vlakova preciznog nivelmana – II.red,
- 49 nivelmanskih vlakova gradskog nivelmana – II. red,
- 149 nivelmanskih vlakova tehničkog nivelmana povećane točnosti – III. red,
- 112 nivelmanskih vlakova tehničkog nivelmana – IV. red.
*
Predstavljeno na Znanstveno-stručnom simpoziju u povodu 40. godišnjice samostalnog djelovanja
Geodetskog fakulteta Sveučilišta u Zagrebu, održanom u Zagrebu 26.9.2002. godine. Objavljeno u
Zborniku radova Simpozija (Rožić, N.: Točnost visinske osnove geometrijskog nivelmana na teritoriju
Republike Hrvatske. Zbornik radova znanstveno-stručnog simpozija povodom 40. godišnjice
samostalnog djelovanja Geodetskog fakulteta Sveučilišta u Zagrebu, Geodetski fakultet, Zagreb, 2002,
105-115).
- 25 -
Navedeni nivelmanski radovi uglavnom su izvedeni u razdoblju od 1946. do 1973. godine, jer
nakon 1973. godine, tj. trenutka dovršenja izmjere IINVT, nije više bilo sustavne generalne nivelmanske
izmjere. Radovi su u cjelini oslonjeni na visinski sustav bivše Austro-Ugarske monarhije (visinski datum,
vrsta visina). Jedina iznimka su radovi IINVT koji su trebali poslužiti za definiranje okosnice novog
visinskog sustava bivše Jugoslavije. Također, nakon 1973. godine nisu obavljani nikakvi sustavni radovi
obnove polja repera, odnosno reniveliranja ili osuvremenjivanja nivelmanskih vlakova i mreža. Izvorni
podaci mjerenja, uporabljen instrumentarij, metode rada, tehnički normativi, rezultati računske obrade
mjerenja, rezultati izjednačenja, uporabna dokumentacija (skice mreža, skice vlakova, položajni opisi
repera, popisi visina) i drugi podaci, pohranjeni su u arhivu Državne geodetske uprave. Iako u potpunosti
arhivski necjeloviti te sistematizirani i tehnološki pohranjeni na način primjeren trenutku njihovog
nastanka, ovi podaci su i danas uporabljivi i mogu se koristiti za različite namjene.
Početkom devedesetih godina, a nakon osamostaljenja i stjecanja suvereniteta Republike
Hrvatske, pristupilo se sustavnim radovima geometrijskog nivelmana sa svrhom sređenja naslijeđene
visinske osnove i njene uporabe u novim okolnostima. Ovi radovi, izvedeni tijekom devedesetih godina,
nisu obuhvatili reniveliranje i obnovu polja repera zbog visoke cijene koštanja terenskih aktivnosti
(stabilizacija, izmjera i dr.), već su se obzirom na ekonomske, financijske, organizacijske (instrumentarij,
oprema, stručnjaci) i druge uvjete temeljili na maksimalnoj uporabi postojećih (arhivskih) podataka
geometrijskog nivelmana, odnosno malim dijelom na izvedbi novih nivelmanskih vlakova. U sklopu tih
radova obavljen je opsežan posao koji se sažeto može objediniti sljedećim cjelinama:
- izrađena je Studija o sređivanju geometrijskog nivelmana na području Republike Hrvatske u kojoj
je ocijenjeno naslijeđeno stanje državnih nivelmanskih mreža i dan prijedlog za poboljšanje tog
stanja (Klak i dr. 1992),
- izrađen je prijedlog Pravilnika o radovima geometrijskog nivelmana (Klak i dr. 1993) koji je
poslužio kao normativno-tehnička osnova za obavljanje radova geometrijskog nivelmana
općenito, odnosno obavljanje revizije polja repera i nivelmanskih mreža,
- obavljena je opsežna i sustavna terenska revizija svih polja repera na teritoriju Republike
Hrvatske obuhvaćenih državnim mrežama geometrijskog nivelmana te je utvrđeno, za svaki
pojedini reper polja i polja repera u cjelini, stanje očuvanosti i uništenosti,
- obavljena je sustavna revizija uporabne dokumentacije polja repera, uključujući:
osuvremenjivanje, usklađivanje s rezultatima terenske revizije, izradu novih preglednih karata
vlakova i mreža te položajnih opisa repera,
- obavljena je opsežna računska obrada i izjednačenje podataka mjerenja geometrijskih
nivelmana, uz njihovu presistematizaciju i oslanjanje na novi visinski datum i temeljnu
nivelmansku mrežu te su određene nove nadmorske visine za sve repere (Klak i dr. 1994, Klak i
dr. 1995., Klak i dr. 1995a, Klak i dr. 1996, Klak i dr. 1996a, Klak i dr. 1997a, Klak i dr. 1998a,
Klak i dr. 1998b, Rožić i dr. 1999, Klak i dr. 1999, Klak i dr. 1999a, Klak i dr. 1999b, Rožić i Feil
2000),
- započeto je publiciranje uporabnih podataka polja repera u posebnim publikacijama u izdanju
Državne geodetske uprave (Klak i dr. 1994a, Klak i dr. 1998c, Rožić i dr. 2001),
- projektirana su i izmjerena tri nova vlaka nivelmana visoke točnosti (Koprivnica – Goričan,
Virovitica – Terezino polje, Batina – Udvar) sa svrhom povezivanja nivelmanskih mreža
geometrijskog nivelmana I. reda između Republike Mađarske i Republike Hrvatske (Klak i dr.
1995b, Klak i dr. 1997b, Klak i dr. 2000),
- definiran je geopotencijalni i normalni sustav visina Republike Hrvatske te je obavljeno
povezivanje visinskog sustava Republike Hrvatske s Ujedinjenom europskom nivelmanskom
mrežom – "United European Levelling Network – UELN" (Klak i dr. 1997, Klak i dr. 1997c, Klak i
dr. 1998, Feil i Rožić 2000),
- podnesena su izvješća o stanju radova generalnog geometrijskog nivelmana na teritoriju
Republike Hrvatske na EUREF Simpozijima (Feil i dr. 1999, Feil i dr. 1999a, Rožić i dr. 2000),
- izrađen je prijedlog za uvođenje u službenu uporabu novog visinskog datuma HRVD71 - Hrvatski
visinski datum 1971 i visinskog sustava Republike Hrvatske HRVRS71 - Hrvatski visinski referentni
sustav 1971 (Feil i Rožić 2000a) koji je ocijenjen od strane međunarodnih savjetnika (Brockman i
dr. 2001),
- izrađena je Studija o obnovi i održavanju visinskog sustava Republike Hrvatske s analizom
rezultata obavljenih radova u razdoblju 1992.-2001. godine i prijedlozima neophodnih radova u
budućem razdoblju (Feil i Rožić 2001).
Jedna od važnih i prethodno navedenih cjelina je računska obrada i izjednačenje nivelmanskih
mjerenja sa svrhom određivanja nadmorskih visina repera. Sastavni dio te obrade je i određivanje
kriterija ocjene točnosti. Obzirom da je obrada obavljena za nivelmanske vlakove na cjelokupnom
teritoriju Republike Hrvatske dobiveni su konkretni pokazatelji točnosti nivelmanskih mjerenja i visinske
točnosti repera.
- 26 -
2. IZJEDNAČENJE NIVELMANSKIH MREŽA GEOMETRIJSKOG NIVELMANA
Računska obrada nivelmanskih mjerenja, odnosno izjednačenje vlakova i mreža geometrijskog
nivelmana na teritoriju Republike Hrvatske, obavljeno je postupno i kontinuirano u razdoblju od 1994. do
2000. godine. Pratilo je obavljanje terenske revizije polja repera, a temeljilo se na rezultatima te revizije i
dostupnoj arhivskoj dokumentaciji, primarno arhiva Državne geodetske uprave Republike Hrvatske i
sekundarno arhiva nekoliko geodetskih tvrtki: Zavod za fotogrametriju d.d. iz Zagreba, Geodetski zavod d.d.
iz Splita i Geodetski zavod d.d. iz Osijeka. Nivelmanske mreže su računski jednoobrazno obrađene i
izjednačene sukladno hijerarhijskom načelu, tj. oslanjanjem nižih redova geometrijskog nivelmana na više
redove. Kao osnova za uvrštenje mreža nižih redova (PN, GN, TNPT i TN) usvojen je novi visinski datum
Republike Hrvatske i mreža IINVT kao temeljna državna nivelmanska mreža, sl. 1.
14
FR3053
Varaždin
15
16
FR3020
Zagreb
III
1
BP82
Rovinj
12
5
FR1029
BV
Brajkovići
2
MCXVII
Bakar
11
9
I
10
C46
Senj
21
IV
CP695
Kostajnica
DCCLIII
Virovitica
A437
Novska
20
37
VIII
C650
Okučani
44
41
18
BV11530
Daruvar
19
O362
Batina
17 C143
Pčelić
42
K274 43
Našice
38
FR3063
Strizivojna
22
MCCI
Ž.Lokva
CP317
Osijek
48
REPUBLIKA HRVATSKA
23
26
V
0
10
20
30
40
50 km
Tumač znakova:
25
C162
Šibenik
31
3
čvorni reper
VI
BV14530
mareograf
nivelmanski vlak
MCCC
Split
PN167
30
br. nivel. vlaka
XIV
35
C346
Opuzen
63
Geodetski Fakultet
XV
FR1098
XVI
C620
Dubrovnik
4
A496
62
60
Slika 1. Nivelmanska mreža IINVT na teritoriju Republike Hrvatske.
Izjednačenja mreža su obavljena primjenom funkcijskog modela posrednih regularnih
nekoreliranih mjerenja i metode najmanjih kvadrata. Težine mjerenja su određene na uobičajeni način u
geometrijskom nivelmanu, tj. recipročno duljinama nivelmanskih vlakova. Podaci mjerenja, nakon
prevođenja iz analognog u digitalni oblik, sadržani su i pohranjeni u računalnim datotekama programskog
sustava LOTUS 123, dok su izjednačenja obavljena primjenom programskog sustava NIVEL (Rožić
1992). Nivelmanske mreže i vlakovi računski su obrađeni i izjednačeni zasebno po pojedinim
nivelmanskim poligonima IINVT, sl. 1. Na taj je način obrada podataka razdijeljena na nekoliko faza.
Rezultati obrade su slijedno publicirani u nizu elaborata Geodetskog fakulteta Sveučilišta u Zagrebu.
Terenska revizija, računska obrada i izjednačenje obavljeni su, prema vremenskom tijeku izvedbe
radova, u sljedećim fazama:
- II. nivelmanski poligon IINVT - 1994. godine,
- I. nivelmanski poligon IINVT - 1995. godine,
- III. nivelmanski poligon IINVT - 1995. godine,
- VIII. nivelmanski poligon IINVT - 1996. godine,
- IV. nivelmanski poligon IINVT - prvi dio - 1996. godine,
- VI., XIV., XV. i XVI. nivelmanski poligon IINVT - 1997. godine,
- V. nivelmanski poligon IINVT - 1998. godine,
- IV. nivelmanski poligon IINVT - drugi dio - 1998. godine,
- 27 -
- III. i VIII. nivelmanski poligon IINVT - dopune - 1999. godine,
- VIII. nivelmanski poligon IINVT - dopuna - 1999. godine,
- IX. nivelmanski poligon IINVT - 1999. godine,
- XII nivelmanski poligon IINVT - 1999. godine,
- VII. i XI. nivelmanski poligon IINVT i otočke nivelmanske mreže - 2000. godine.
Svakoj od prethodno navedenih faza odgovara i zaseban elaborat Geodetskog fakulteta (Klak i
dr. 1994, Klak i dr. 1995., Klak i dr. 1995a, Klak i dr. 1996, Klak i dr. 1996a, Klak i dr. 1997a, Klak i dr.
1998a, Klak i dr. 1998b, Rožić i dr. 1999, Klak i dr. 1999, Klak i dr. 1999a, Klak i dr. 1999b, Rožić i Feil
2000) u kojem se nalaze navedeni svi detalji računske obrade i izjednačenja, odnosno njihovi rezultati.
Važno je naglasiti da su izjednačenja nivelmanskih mreža nižih redova provedena bez potrebe
obavljanja dopunskih terenskih mjerenja, a u svrhu njihovog povezivanja s mrežom IINVT kao
okosnicom. Naime, geometrijske konfiguracije mreža Austrijskog preciznog nivelmana i INVT ne
podudaraju se s geometrijskom konfiguracijom mreže IINVT (Rožić 2001), ali je obzirom na primjerenu
razinu njihove međusobne isprepletenosti postojala dobra osnova za povezivanje i bez dopunskih
mjerenja. Također, usvajanjem mreže IINVT za okosnicu visinskog sustava, svi su vlakovi INVT u
izjednačenja uvršteni kao vlakovi preciznog nivelmana.
Također, neophodno je upozoriti i na činjenicu da je u sklopu izjednačenja obrađen opažački
materijal koji pripada različitim vremenskim epohama. Naime, zajednički su obrađeni podaci mjerenja koji se
odnose na dulje vremensko razdoblje izmjere. Okosnica visinskog sustava je najmlađa i najkvalitetnija
visinska mreža (IINVT), dok je veći dio radova nivelmana nižih redova točnosti stariji od nje i do 25 godina.
Zato su u rezultatima izjednačenja sadržani i utjecaji recentnih pomaka Zemljine kore, regionalni visinski
pomaci izazvani geodinamičkim silama i pomaci repera izazvani nestabilnošću njihovih mikrolokacija.
3. OCJENA TOČNOSTI GEOMETRIJSKOG NIVELMANA
Točnost radova geometrijskog nivelmana na cjelokupnom teritoriju Republike Hrvatske daju
jednoobrazno određeni kriteriji točnosti "a posteriori", tj. referentne vjerojatne pogreške mjerenja i
vjerojatne pogreške visina čvornih repera određene na temelju izjednačenja nivelmanskih mreža. Po
pojedinim redovima nivelmana i nivelmanskim poligonima IINVT, ovi su podaci sadržani u već citiranim
elaboratima Geodetskog fakulteta (Klak i dr. 1994, Klak i dr. 1995., Klak i dr. 1995a, Klak i dr. 1996, Klak i
dr. 1996a, Klak i dr. 1997a, Klak i dr. 1998a, Klak i dr. 1998b, Rožić i dr. 1999, Klak i dr. 1999, Klak i dr.
1999a, Klak i dr. 1999b, Rožić i Feil 2000). Osim izjednačenja temeljne nivelmanske mreže, tj. mreže
IINVT (Rožić 1995), obavljeno je ukupno 127 izjednačenja mreža geometrijskih nivelmana nižih redova
točnosti, različite razine složenosti u pogledu broja mjerenja i nepoznanica. Po pojedinim redovima obavljeno
je izjednačenje:
- 16 mreža preciznih nivelmana,
- 58 mreža gradskih nivelmana,
- 19 mreža tehničkih nivelmana povećane točnosti,
- 34 mreže tehničkih nivelmana.
U slučaju izrazito velikih mreža, posebno gradskih nivelmana, npr. Zagreba, Rijeke, Splita, Osijeka,
odnosno nekih tehničkih nivelmana, izjednačenja su obavljena u nekoliko dijelova i to ili razdvajanjem mreža
na glavnu i sporedne mreže ili razdvajanjem mreža na nekoliko neovisnih dijelova definiranih sukladno
njihovim odnosom prema vlakovima višeg reda.
U objedinjenom obliku kriteriji točnosti "a posteriori" navedeni su u tablici 1, raščlanjeni po pojedinim
nivelmanskim poligonima IINVT i pojedinim redovima nivelmana. U tablicu su uvrštene referentne vjerojatne
pogreške mjerenja uo i vjerojatne pogreške visina čvornih repera uH. Navedene su uvijek po dvije vjerojatne
pogreške visina čvornih repera. Vjerojatna pogreška visine čvornog repera koja je poprimila najniži iznos
(min.- mH) i vjerojatna pogreška visine čvornog repera koja je poprimila najviši iznos (max.- mH). Reperi na
koje se odnose ove vjerojatne pogreške imaju najvišu, odnosno najnižu visinsku točnost. Stoga, ove su
vjerojatne pogreške dobri pokazatelji točnosti visina svih drugih čvornih repera obuhvaćenih izjednačenjima.
Tablica 1. Ocjena točnosti mjerenja i visina čvornih repera (vjerojatne pogreške).
IINVT
POLIG.
uo
mm / km
I.
± 0,79
PN
min.uH max.uH
mm
± 0,33
mm
±11,77
uo
mm / km
GN
min.uH max.uH
mm
mm
uo
TNPT
min.uH max.uH
mm
mm / km
mm
uo
mm / km
TN
min.uH max.uH
mm
mm
± 1,86
± 1,41
± 7,09
± 2,92
± 0,26
± 5,21
± 1,87
± 3,08
± 7,77
II.
± 4,59
± 6,04
±35,15
± 1,25
± 0,23
± 2,16
± 3,20
± 2,43
± 8,53
III.
± 2,56
± 1,61
±10,01
± 3,25
± 0,47
± 4,63
± 3,97
± 3,73
±14,25
- 28 -
uo
mm / km
min.uH max.uH
mm
mm
± 3,89
± 2,49
± 8,72
± 6,09
± 1,21
±14,31
IV.
± 2,28
± 3,67
±10,23
± 2,10
± 1,03
± 2,07
V.
± 2,14
± 2,44
± 9,20
± 2,31
± 0,50
± 2,37
VI.
± 2,03
± 1,14
± 6,06
± 3,03
± 0,31
± 3,86
± 6,55
±12,09
±12,09
VII.
VIII.
± 2,47
± 2,29
± 9,14
± 2,75
± 0,55
± 4,11
IX.
± 1,15
± 1,24
± 9,59
± 4,84
± 0,57
± 4,73
XI.
XII.
XIV.
± 1,15
± 1,65
± 1,24
± 4,51
± 9,59
± 4,77
XV.
OTOCI
± 3,33
± 1,76
± 5,10
± 0,51
± 7,17
± 1,22
± 1,33
± 3,35
±25,92
± 6,73
± 6,59
±16,53
± 8,18
± 0,89
±19,20
± 3,57
± 3,48
± 6,50
± 5,60
± 2,47
±11,29
± 2,27
± 5,41
± 5,52
± 6,95
± 4,10
± 7,83
± 3,33
± 4,48
± 7,51
± 8,05
± 4,62
±23,67
± 3,96
± 2,99
±12,03
± 1,47
± 5,55
± 6,35
±11,85
±16,41
±27,93
± 3,41
± 1,08
± 5,98
Na temelju podataka tablice 1 mogu se odrediti reprezentativne vrijednosti kriterija točnosti "a
posteriori" koje se odnose na pojedine redove geometrijskih nivelmana za cjelokupan teritorij Republike
Hrvatske. Tako je za nivelmansku mrežu IINVT referentna vjerojatna pogreška mjerenja
(1)
u o = ±0.79 mm / km ,
i vjerojatne pogreške visine čvornih repera mreže s najvišom (min.) i najnižom (max.) visinskom točnošću:
(2)
min.
u H = ±0.33mm,
max.
(3)
u H = ±11.77 mm.
Za mreže preciznog nivelmana (PN) reprezentativna vrijednost referentne vjerojatne pogreške
mjerenja jest
(4)
u o = ±2.53mm / km ,
i vjerojatne pogreške visina čvornih repera mreže:
(5)
min.
u H = ±1.14mm,
(6)
max.
u H = ±35.15mm.
Za mreže gradskih nivelmana (GN) reprezentativna vrijednost referentne vjerojatne pogreške
mjerenja jest
(7)
u o = ±2.70 mm / km ,
(8)
min.
u H = ±0.23mm,
max.
(9)
u H = ±7.17 mm.
Za mreže tehničkih nivelmana povećane točnosti (TNPT) reprezentativna vrijednost referentne
vjerojatne pogreške mjerenja jest
(10)
u o = ±3.42 mm / km ,
(11)
min.
u H = ±2.43mm,
max.
(12)
u H = ±14.25mm.
Konačno, za mreže tehničkih nivelmana (TN) reprezentativna vrijednost referentne vjerojatne
pogreške mjerenja jest
(13)
u o = ±6.61mm / km ,
i vjerojatne pogreške visina čvornih repera mreže
(14)
min.
u H = ±0.89mm,
(15)
max.
u H = ±27.93mm.
4. ANALIZA OCJENE TOČNOSTI I ZAKLJUČCI
Na temelju podataka ocjene točnosti navedenih u prethodnom poglavlju može se donijeti nekoliko
zaključaka. Prije svega, temeljem izraza (1), (4), (7), (10) i (13) može se zaključiti da na ukupnom teritoriju
Republike Hrvatske postignute točnosti mjerenja u svim redovima nivelmana uglavnom zadovoljavaju
unaprijed postavljene kriterije točnosti, utvrđene prijedlogom Pravilnika o radovima geometrijskog nivelmana
(Klak i dr. 1993) i da se točnost mjerenja logično smanjuje od viših prema nižim redovima. U prijedlogu
Pravilnika su određene dopuštene vrijednosti referentnih vjerojatnih pogrešaka mjerenja za pojedine redove
geometrijskog nivelmana i to:
- 29 -
-
nivelman visoke točnosti, uo = ±1mm / km ,
-
precizni i gradski nivelman, uo = ±2mm / km ,
-
tehnički nivelman povećane točnosti, uo = ±5mm / km ,
- tehnički nivelman, uo = ±8mm / km .
Jedine, relativno male, iznimke su precizni i gradski nivelmani kod kojih je točnost mjerenja
neznatno niža nego je kriterijima točnosti dopušteno. Ove razlike su prihvatljivog reda veličine, posebno
obzirom na različite vremenske epohe kojima pripadaju podaci IINVT u odnosu na epohe preciznog i
gradskih nivelmana.
Ipak, podaci ocjene točnosti mjerenja navedeni u tablici 1, pokazuju da na teritoriju Republike
Hrvatske nije postignuta, u okviru pojedinih redova geometrijskog nivelmana, u potpunosti homogena
točnost. Razvidno je da je na pojedinim dijelovima njenog teritorija, tj. u pojedinim poligonima IINVT, točnost
mjerenja u okviru istih redova nivelmana različita i ponekad izrazitije niža nego je to dopušteno. Izvori ove
nehomogenosti primarno su vezani uz kvalitetu izmjere, postupke pri mjerenju, instrumentarij i druge uvjete.
Sekundarno, posljedica su različitih vremenskih epoha kojima pripadaju pojedini redovi nivelmana, a
izjednačeni su hijerarhijskim uklapanjem mreža nižih redova u fiksni (zadani) okvir mreža viših redova.
Visinska točnost repera, sudeći na temelju točnosti visina čvornih repera, može se smatrati
zadovoljavajućom i logičnom u odnosu na točnost mjerenja. U cjelokupnom preciznom nivelmanu, uzevši
u obzir čitav državni teritorij, čvorni reper s najnižom točnošću visine ima vjerojatnu pogrešku od ± 35
mm, u gradskom i tehničkom nivelmanu povećane točnosti od ± 7mm, odnosno od ± 14 mm te u
tehničkom nivelmanu od ± 28mm. Veliki broj čvornih repera ima i znatno višu točnost visina, što je zorno
vidljivo u podacima tablice 1. Pri tom, treba uzeti u obzir da su točnosti visina čvornih repera dijelom
uvjetovane i načinom izjednačenja mreža, tj. pretpostavkom bespogrešnosti repera viših redova
nivelmana. Zanimljiv je i odnos točnosti visina repera slijedno po različitim redovima, od najvišeg prema
najnižem. Najniža točnost visina repera pretežno se javlja u preciznom nivelmanu, dok je u ostalim
redovima nivelmana viša nego u preciznom nivelmanu. U tim nivelmanima, od gradskih do tehničkih,
točnost se suvislo smanjuje s redom nivelmana. Ova nelogičnost u razdiobi visinske točnosti repera, jer
visinska točnost bi se od nivelmana visoke točnosti trebala postupno smanjivati prema tehničkom
nivelmanu, također je vjerojatno posljedica različitih vremenskih epoha kojima pripada mreža IINVT i
mreže popunjavajućih nivelmana.
Postignute točnosti mjerenja i visinske točnosti repera, do određene su mjere i iznenađujuće.
Naime, uzevši u obzir činjenicu da je na hijerarhijskom načelu izjednačen opažački materijal prikupljen
izmjerom iz dugog vremenskog razdoblja i bitno različitih vremenskih epoha, mjeren različitim
instrumentarijem, postupcima i priborom te najvećim dijelom prikupljen u vrlo skromnim materijalnotehničkim uvjetima (razdoblje od 1945. do 1963. godine), dobiven je relativno zadovoljavajući rezultat.
Bez obzira na određene nedostatke koje radovi geometrijskog nivelmana svakako sadrže, još uvijek
imaju primjerenu uporabnu vrijednost, posebno za praktične potrebe. Uostalom, u ovom trenutku
Republika Hrvatska ne raspolaže kvalitetnijim nivelmanskim radovima koje bi mogla uvesti u službenu
uporabu, a novi sustavni radovi na obnovi polja repera i osuvremenjivanju državnih mreža geometrijskog
nivelmana još uvijek nisu započeti.
LITERATURA
Brockmann, E., Harsson, B.G., Ihde, J. (2001): Geodetic Reference System of the Republic of Croatia,
Consultants Final Report on Horizontal and Vertical Datum Definition, Map projection and Basic
Networks, Tehnical Report, June 2001.
Feil, L., Klak, S., Rožić, N., Gojčeta, B. (1999): National report of the Republic of Croatia on the high
system, Mitteilungen des Bundesamtes für Kartographie und Geodäsie, Band 6, EUREF
Publication No. 7/I, Frankfurt am Main, 142-148.
Feil, L., Klak, S., Rožić, N., Gojčeta, B. (1999): National report of the Republic of Croatia on the Height
System, Veröffentlichungen der Bayerischen Kommission für die Internationale Erdmessung der
Bayerischen Akademie der Wissenschaften, Report on the Symposium of the IAG
Subcommission for Europe (EUREF) held in Prague, 2-5 June 1999, München, Heft Nr. 60, 146149.
Feil, L., Rožić, N. (2000): UELN geopotencijalni i normalni visinski sustav Republike Hrvatske, Geodetski
Feil, L., Rožić, N. (2000a): Prijedlog službenog visinskog datuma Republike Hrvatske, Geodetski fakultet
Feil, L., Rožić, N. (2001): Studija o obnovi i održavanju visinskog sustava Republike Hrvatske, Geodetski
- 30 -
Klak, S., Feil, L., Rožić, N. (1992): Studija o sređivanju geometrijskog nivelmana na području Republike
Hrvatske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Klak, S., Feil, L., Rožić, N. (1993): Pravilnik o radovima geometrijskog nivelmana – prijedlog, Geodetski
Klak, S., Feil, L., Rožić, N. (1994): Izjednačenje nivelmanskih mreža svih redova u II. nivelmanskom
poligonu II.NVT, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Klak, S., Feil, L., Rožić, N. (1994a): Podaci o reperima - knjiga 1, Državna geodetska uprava Republike
Hrvatske, Zagreb, 1994.
Klak, S., Feil, L., Rožić, N. (1995): Izjednačenje nivelmanskih mreža svih redova u I. nivelmanskom
Klak, S., Feil, L., Rožić, N. (1995a): Izjednačenje nivelmanskih mreža svih redova u III. nivelmanskom
Klak, S., Feil, L., Rožić, N. (1995b): Povezivanje nivelmana visoke točnosti Republike Hrvatske,
Republike Slovenije i Republike Mađarske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Klak, S., Feil, L., Rožić, N. (1996): Izjednačenje nivelmanskih mreža svih redova u VIII. nivelmanskom
Klak, S., Feil, L., Rožić, N. (1996a): Izjednačenje nivelmanskih mreža svih redova u IV. nivelmanskom
poligonu II.NVT - prvi dio, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Klak, S., Feil, L., Rožić, N. (1997): Ispitivanje mogućnosti određivanja geopotencijalnih visina, Geodetski
Klak, S., Feil, L., Rožić, N. (1997a): Izjednačenje nivelmanskih mreža svih redova u VI., XIV., XV. i XVI.
nivelmanskom poligonu II.NVT, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Klak, S., Feil, L., Rožić, N. (1997b): Povezivanje nivelmana visoke točnosti Republike Hrvatske i
Republike Mađarske, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Klak, S., Feil, L., Rožić, N. (1997c): Precise levelling data of the Republic of Croatia for the United
European Levelling Network, Državna geodetska uprava Republike Hrvatske, Zagreb.
Klak, S., Feil, L., Rožić, N. (1998): Connecting of levelling of high accuracy between the Republic
Hungary and the Republic of Croatia in geopotential height system. Geodetski fakultet
Klak, S., Feil, L., Rožić, N. (1998a): Izjednačenje nivelmanskih mreža svih redova u V. nivelmanskom
Klak, S., Feil, L., Rožić, N. (1998b): Izjednačenje nivelmanskih mreža svih redova u IV. nivelmanskom
poligonu II.NVT - drugi dio, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Klak, S., Feil, L., Rožić, N. (1998c): Podaci o reperima - knjiga 2, Državna geodetska uprava Republike
Hrvatske, Zagreb.
Klak, S., Feil, L., Rožić, N. (1999): Izjednačenje nivelmanskih mreža svih redova u VIII. nivelmanskom
poligonu II.NVT – dopuna, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Klak, S., Feil, L., Rožić, N. (1999a): Izjednačenje nivelmanskih mreža svih redova u IX. nivelmanskom
Klak, S., Feil, L., Rožić, N. (1999b): Izjednačenje nivelmanskih mreža svih redova u XII. nivelmanskom
Klak, S., Feil, L., Rožić, N. (2000): Povezivanje nivelmana visoke točnosti Republike Hrvatske i
Republike Mađarske - drugi dio, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Rožić, N. (1992): Kompjutorski program za izjednačenje nivelmanskih mreža – NIVEL, Geodetski fakultet
Sveučilišta u Zagrebu, Zagreb, 1992.
Rožić N. (1995): Ispitivanje slučajnih i sistematskih pogrešaka u geometrijskom nivelmanu, Geodetski
fakultet Sveučilišta u Zagrebu, Zagreb, doktorska disertacija, Zagreb.
Rožić, N., Feil, L. (2000): Izjednačenje nivelmanskih mreža svih redova u VII. i XI. nivelmanskom
poligonu II.NVT i izjednačenje otočkih nivelmanskih mreža, Geodetski fakultet Sveučilišta u
Zagrebu, Zagreb.
Rožić, N., Feil, L., Pavičić, S. (2000): Review of Activities on Levelling Works in the Republic of Croatia
1999-2000, Veröffentlichungen der Bayerischen Kommission für die Internationale Erdmessung
der Bayerischen Akademie der Wissenschaften, Report on the Symposium of the IAG
Subcommission for Europe (EUREF) held in Tromsø, 22-24 June 2000, München, Heft Nr. 61,
362-365.
Rožić, N., Feil, L., Pavičić, S. (2001): Podaci o reperima - knjiga 3, Državna geodetska uprava Republike
Hrvatske, Zagreb.
Rožić, N., Klak, S., Feil L. (1999): Izjednačenje nivelmanskih mreža svih redova u III. i VIII.
nivelmanskom poligonu II.NVT – dopune, Geodetski fakultet Sveučilišta u Zagrebu, Zagreb.
Croatia, Acta Geodaetica et Geophysica Hungarica, Budapest, Vol. 36 (2), 231-243.
- 31 -
- 32 -
STATUS OF THE CROATIAN FIRST ORDER GRAVITY NETWORK*
Željko Hećimović, Nevio Rožić, Tomislav Bašić, Danko Markovinović
ABSTRACT
Since Croatian Geodetic Institute (CGI) started to work in December 2001 preliminary work
regarding measurements of the Croatian First Order Gravity Network has been carried out. The network
will be connected to the Croatian Zero Order Gravity Network. For measurements of the Croatian First
Order Gravity Network two Scintrex CG-3M gravimeters are prepared: HGI-1 and HGI-2. Their behavior
and capabilities are systematically analyzed: drift, temperature compensation, tilt sensor zero
adjustment, tilt sensor sensitivity adjustment, tilt sensor cross coupling, battery check and gravimeter
clock drift. In this period drifts of the both gravimeters become more linear, and that is improvement of
the main gravimeter characteristic. To analyze structure of a gravimeter signal in detail, stability of the
HGI-2 gravimeter was analyzed using wavelet multiresolution technique. To verify gravimeters in the
fieldwork, test measurements were done. Design of the test gravity network contains two absolute
gravimetric points. That is giving opportunity for reliable verification of the gravimeters. Gravimeters
analysis is showing that they can be used in measurements of the Croatian First Order Gravity Network.
1. INTRODUCTION
A project of establishing new Croatian First Order Gravity Network is one of the projects that
Croatian State Geodetic Administration (SGA) implemented in a five years plan "State Survey and Real
Estate Cadastre" that is supported by Croatian government.
All gravimetric works in Croatia are going to be connected to the Zero Order Gravity Network
(see Fig. 1). It was established in the projects: Connection of the Republic of Croatia to international
absolute gravity network and UNIfication of GRAvity systems in Central Europe (UNIGRACE). Absolute
measurements were done by Bundesamt für Kartographie und Geodäsie (BKG) from Frankfurt am Main
(Germany) and Ecole et Observatorie des Sciences de la Terre (EOST) from Strasbourg (France). Zero
Order Gravity Network includes six absolute gravity points: Zagreb - Puntijarka, Zagreb - Maksimir,
Osijek, Pula, Makarska and Dubrovnik (Čolić et al., 1997; Čolić et al., 2000; Medak et al., 2001a; Medak
et al., 2001b; Marjanović, 2002). The new Croatian First Order Gravity Network will be connected to the
Croatian Zero Order Gravity Network and data of absolute points are checked and systemized.
Revision of the Croatian part of former Yugoslavia gravity network, and proposal for new
Croatian First Order Gravity network was made by the Faculty of Geodesy University of Zagreb (Bašić et
al., 2001, Markovinović, 2001).
The proposal includes design of the new gravity network and national calibration line (see Fig. 1
and 2). The New Croatian First Order Gravity Network includes 36 points on the land, and 15 points
should be placed on the islands.
Croatian calibration line consists of 10 points in north-south direction (see Fig. 2). Three points
are absolute gravimetric points. The differences in latitude of the first and the last point is ≈ 2° 32' (≈ 270
km) (Markovinović and Rezo, 2002).
Croatian Geodetic Institute (CGI) is a new institution. It started to work in December 2001. In that
time Zero Order Gravity Network was already defined and design of the First Order Gravity Network was
determined.
2. GRAVIMETERS PREPARATION FOR MEASUREMENT OF THE I. ORDER GRAVITY NETWORK
After establishment and foundation of the CGI two relative Scintrex CG-3M gravimeters (HGI-1
and HGI-2) were received from SGA. They will be used in measurement of the First Order Gravity
Network. Before using the relative gravimeters in measurements of state gravity networks they should be
proofed and analyzed. They should satisfy measurement criteria. Considering the problem, extensive
work has been done. It includes: gravimeters initial verifying, systematic analysis of gravimeters main
održanom u Toledu, Španjolska, 3.-8.6.2003. godine. Objavljeno u zborniku radova Simpozija
(Hećimović, Ž., Rožić, N., Bašić, T., Markovinović, D.: Status of the Croatian First Order Gravity Network.
Mitteilungen des Bundesamtes für Kartographie und Geodäsie, Band 33, EUREF Publication No. 13,
Frankfurt am Main, 2004, 306-310).
*
- 33 -
characteristics, analysis of measurements system stability and drift, gravimeter testing on the basis of
field measurements and calibration.
Fig. 1 Croatian Zero (squares) and the First
Order Gravity Networks (triangles)
Fig. 2 Croatian calibration line
3. GRAVIMETERS INITIAL CHECKING
During initial verifying of gravimeters HGI-1 and HGI-2 functionality it was discovered that
operating systems in both gravimeters had millennium bug. After contacting the gravimeters
manufacturer Scintrex, new operating systems were received and replaced in the both gravimeters.
Another delay of using gravimeter HGI-1 was caused by the malfunctioning of temperature
sensor. The gravimeter was repaired in Scintrex (Canada).
After repairing it, the same gravimeter experienced reading jumps (tare). The analysis of problem
showed that the reading jumps were caused by change of a rate of an artificial, man made, micro seismic
in the building where measurements were done (Hećimović, 2002), and reading jumps were not caused
by malfunctioning of the gravimeter (Hrvatski geodetski institut, 2002a).
4. SYSTEMATIC ANALYSIS OF GRAVIMETERS' MAIN CHARACTERISTICS
After solving the initial problems, the gravimeters have been made fully operable. To prepare
gravimeters for measurements of the national gravity networks their behavior and capabilities are
systematically analyzed. That includes regular checking of: drift, temperature compensation, tilt sensor
zero adjustment, tilt sensor sensitivity adjustment, tilt sensor cross coupling, battery check and
gravimeter clock drift.
Gravimeters are systematically analyzed in the period of about one year. At the beginning of the
analysis period, drifts of both gravimeters were parabolic and at the end of analyzing period, drifts
became more linear. Drifts unlinearities in both gravimeters (HGI-1 and HGI-2) can be clearly recognized
in a longer continuous measurement (see Fig. 3 and 4).
Fig. 3. Readings of the gravimeter HGI-2 at the
beginning of the analysis period
- 34 -
Fig. 4. Readings of the gravimeter HGI-2
at the end of the analysis period
Parabolic drift of the HGI-1 on the beginning of the analysis period can be clearly recognized in
seventeen days continuous measurements (see Fig. 3). Drift of HGI-2 had become more linear with time
and at the end of the analysis period it had much better linearity characteristic (see Fig. 4).
Parabolic drift of the gravimeter HGI-1 at the beginning of the analysis period can be clearly
recognized in two weeks continuous measurements (see Fig. 5). At the end of the analysis period drift of
HGI-1 had much better linearity characteristic (see Fig. 6).
Fig. 5. Readings of the gravimeter HGI-1 at the
beginning of the analysis period
Fig. 6. Readings of the gravimeter HGI-1
at the end of the analysis period
Drifts are significantly improved in both gravimeters. That is improvements of the main
gravimeters characteristic. Other gravimeters characteristics, that are systematically analyzed, are
indicating normal behavior of the gravimeters.
5. ANALYSIS OF GRAVIMETER MEASUREMENTS SYSTEM STABILITY
Stability of the measurements system is also one of the main gravimeter characteristics. It has
long and short time characteristic.
Long-term stability of gravimeters HGI-1 and HGI-2 is analyzed using drift changes in the period
of about one year (see Fig. 7 and 8).
Fig. 7. Drift of HGI-1
Fig. 8. Drift of HGI-2
Drift change of the gravimeter HGI-1 is showing irregular behavior, but the amplitudes are
significantly smaller than by the gravimeter HGI-2. Drift of the gravimeter HGI-2 has decreasing trend,
but drift changes are significantly bigger than by the HGI-1. Drift changes of the HGI-2 are smaller in the
second part of analyzing period, and they are showing long time stabilization of the measurements
system of HGI-2.
To analyze the short time stability of the measurements system, the signal of the gravimeter HGI2 was analyzed using wavelet multiresolution technique (Hećimović and Markovinović, 2002). Coifman
wavelet (Coiflet) of the fifth order from the family of orthogonal wavelet was used. Coifman wavelet is
presented on the Fig. 9 and on the Fig. 10 is associated scaling function. Multiresolution was made until
the third level (see Fig. 11).
- 35 -
th
Fig. 9. Coifman wavelet of the 5 order
Fig. 10. Associated scaling function
Fig. 11. Wavelet multiresolution decomposition.
Input in wavelet analysis is one-day continuous measurement signal of gravimeter HGI-2 (see
Fig. 12). Gravimeter readings are in real time corrected for scaling factor, temperature, "a priori" drift,
Earth tides and gravimeter tilt.
Fig. 12. One-day continuous readings used in wavelet analysis.
Fig. 13 is showing wavelet decomposition of the signal: approximation on the third level (A3) and
details on the all three levels (D1, D2 and D3).
The approximation is taking trend and the main part of signal energy. It is free of high frequency
part. In the approximation A3, the remaining signal of half-day period can be recognized (see Fig. 13). It
could be caused by not completely compensated reductions (e.g. Earth tides). Signal disturbances in
-5
-2
approximation (A3) are from 10 to 30 minutes long. They are irregular and smaller then 0,010·10 ms .
They are most probably caused by longer microseisnmic influences on the measurements.
Details are having the characteristic of the noise. With the higher decomposition level, amount of
information in detail is lower and the noise has finer structure. The details are giving insight in the short
-5
time instabilities of the measurement system. Amplitude of detail D1 is 0,017·10 ms
-5
0,015·10
-2
ms
-5
and for D3 is 0,009·10
-2
-2
for D2 is
ms . The detail D1 has period of about one-epoch of
- 36 -
measurements (60 seconds), detail D2 has four epochs and detail D3 has little bit less than then epochs.
In the table 2 there are the main statistical characteristics of the details given, and on Fig. 14 there are
the distributions of the details presented.
Fig. 13. Approximation A3 and decomposed details D1, D2 and D3.
Table 2: Main statistical characteristics of the details.
Fig. 14. Distributions of the details D1, D2 and D3.
6. TEST MEASUREMENTS
To check gravimeters in the fieldwork, test measurements were done. Design of the test gravity
network (see Fig. 15) contains two absolute gravimetric points (1 Zagreb Maksimir and 2 Zagreb
Puntijarka).
- 37 -
Fig. 15. Gravimetric test network 6
To collect the data that can be used for reliable checking of the instruments, star method in all
three combinations is used.
-5
-2
After measurements reductions and drift corrections a priori closure of figure is 0,011·10 ms for
-5
-2
gravimeter HGI-1 and 0,013·10 ms for gravimeter HGI-2. Network datum is defined with two absolute
-5
-2
points. After adjustment, the referent standard deviation is 0,0096·10 ms . The new gravity value of the
-5
-2
third point has difference in comparison to old Yugoslav gravity network of 14,8·10 ms . That is the
difference between datum defined by two absolute gravity points and the old Yugoslav gravity datum
(Hrvatski geodetski institut, 2002b). The old Yugoslav gravity datum, that Croatia was a part of, was
determined by using the datum point in Belgrade.
7. GRAVIMETERS CALIBRATION
Measurements on the two absolute points, that are also a part of the Croatian calibration line, are
-5
-2
used for calibration of gravimeters. Gravity difference between the absolute points is 151·10 ms what is
giving opportunity for calibration. Linear calibration coefficient was determined and imported in memory
of gravimeter. In that way the gravimeters are in real time scaled considering the Croatian calibration
line.
8. CONCLUSIONS
Preliminary work for measurements of the Croatian First Order Gravity Network has been done.
The analysis of gravimeters HGI-1 and HGI-2 is showing tendency of increasing gravimeter
measurements quality and performances. They can be used for measurements of the Croatian national
gravity network. All preparations for measurements of the First Order Gravity Network are done. Faculty
of Geodesy University of Zagreb will do field measurements. They will start this spring.
REFERENCES
Bašić T., Markovinović D., Rezo M., Špoljarić D., Hećimović Ž. (2001): Studija stanja i prijedlog nove
Osnovne gravimetrijske mreže Republike Hrvatske. Geodetski fakultet Sveučilišta u Zagrebu,
Zagreb 2001.
Čolić K., Pribičević B., Špoljarić D., Medak D., Markovinović D., Švehla D., Lelas N. (1997): Izvješće o
radovima na projektu: Pripajanje Republike Hrvatske u svjetsku apsolutnu gravimetrijsku mrežu.
Geodetski fakultet Sveučilišta u Zagrebu, Zagreb 1997.
Čolić K., Pribičević B., Medak D., Đapo A., Ivičević V., Lothammer A., Buljan D. (2000): Elaborat o
izvršenim radovima na projektu: Priključenje Republike Hrvatske u svjetsku apsolutnu
gravimetrijsku mrežu. Geodetski fakultet Sveučilišta u Zagrebu, Zagreb 2000.
Hećimović, Ž., D. Markovinović (2002): Stabilnost mjernog sustava Scintrex HGI-2 gravimetra. Zbornik
znanstveno - stručnog simpozija Geodetskog fakulteta Sveučilišta u Zagrebu povodom 40.
obljetnice samostalnog djelovanja 1962. - 2002., str. 95 - 104, Zagreb 2002.
Hećimović (2002): Reading jumps of HGI-1 Scintrex CG-3M gravimeter. Presented in International
Gravimetry Summer School. Louvain-la-Neuve (Belgija) 3 - 12 September 2002.
- 38 -
Hrvatski geodetski institut (2002a): Izvješće o ispitivanju uzroka skokova u očitanjima gravimetra HGI-1.
Odjel za osnovne geodetske radove, Zagreb 2002.
Hrvatski geodetski institut (2002b): Izvješće o obradi podataka testnih 78 mjerenja Scintrex CG-3M
gravimetrima. Odjel za osnovne geodetske radove, Zagreb 2002.
Marjanović M. (2002): Gravimetrijski radovi. Državna geodetska uprava, Zagreb 2002.
Markovinović D. (2001): Gravimetrijska mreža I. reda i gravimetrijska kalibracijska baza Republike
Hrvatske. Magistarski rad. Geodetski fakultet Sveučilišta u Zagrebu, Zagreb 2001.
Markovinović D., Rezo M. (2002): Basic Gravimetric Network of the Republic of Croatia. Poster Session.
I. Ph.D. Civilexpo, International Ph.D. Conference of Civil Engineering, November 21-22 2002,
Budapest, p. 197-199.
Medak D., Pribičević B., Đapo A., Lothammer A., Luck B. (2001a): Elaborat o izvršenim radovima na
projektu: Priključenje Republike Hrvatske u svjetsku apsolutnu gravimetrijsku mrežu - Druga faza
projekta UNIGRACE. Geodetski fakultet Sveučilišta u Zagrebu, Zagreb 2001.
Medak, D., B. Pribičević, A. Đapo (2001b): Priključenje Republike Hrvatske u svjetsku apsolutnu
gravimetrijsku mrežu - Projekt UNIGRACE. Izvješće o znanstveno-stručnim projektima iz 2000.
godine. Državna geodetska uprava, 23-32, Zagreb 2001.
- 39 -
- 40 -
STRATEGY AND SYSTEM OF QUALITY CONTROL OF THE OFFICIAL
GEOGRAPHIC DATA PRODUCED BY PRIVATE COMPANIES IN CROATIA*
Nevio Rožić
ABSTRACT
Recognizing specific needs of the Republic of Croatia regarding the official geographic
(topographic) data needs in transition period, specific strategy for production of data and quality control
system for produced data are defined by responsible government administration bodies and professional
institutions. The Strategy yields so called "Croatian model" which is based on interaction and
coordination between three main subjects at national level, e.g. State Geodetic Administration (SGA),
Croatian Geodetic Institute (CGI) and private companies licensed for carrying out state survey works.
Each subject has precise role and responsibility in the process of producing geographical (topographical)
data or "geodetic products" specified by SGA product specifications. The products are at disposal to all
users from private persons or companies to governmental and non governmental institutions. The above
mentioned "Croatian model" is still being developed and implemented with so far good results achieved.
Regarding the Croatian Geodetic Institute participation in "model" implementation, the main
objectives are establishment and implementation of the Quality Control System which should provide
efficient, transparent and professional quality control of specified data and/or geodetic products:
topographic (vector) data, topographic maps in the scale of 1:25000 and orthophoto maps in the scale of
1:5000, etc. produced for the Croatian Government by private companies.
1. INTRODUCTION
After acquiring the independence and sovereignty at the beginning of the 90-ties there were
significant and extensive activities initiated in the Republic of Croatia in the field of geodetic and
surveying works, starting and initiating production of geographical (topographical) data and building of a
Spatial Data Infrastructure at the national (state) level. The activities included wide range of working
fields: reorganization of existing state bodies and institutions competent for carrying out geodetic and
surveying work, foundation of new specialized government institution - Croatian Geodetic Institute,
creating new and significantly improved laws and ordinance basis, evaluating, readjusting and using the
inherited geodetic basis from the former state in new circumstances (fundamental state networks,
geodetic datums, cartographic projection, etc.), carrying out new fundamental geodetic works at the state
territory, organizing and motivating Croatian private companies to start producing the geodata and
specific geodetic products for state needs, etc. Among all activities special importance has been given to
the development and renewal of the large program of production of the topographic map series and
orthophoto maps simoultaneously with new cadastral surveys including solving complex problems
connected with land registry inherited from the former state.
Mentioned activities have become very intensive especially after 1995 and they were carried out
during the period from 1995 till today in organized and systematic way, in accordance with objective
Croatian situation determined by internal and external conditions. The great influence made on the whole
process was and still is strongly connected with international and European globalization processes,
democratization of the state and state administration, very fast and quite radical general and specific
technological changes, restructuring, privatization, transition to the market economy and protection of
private ownership, geodetic and surveying heritage from former state, level of organization and efficiency
of Croatian administration and other professional institutions, economic and financial potential of the
state, etc.
In accordance with all conditions which have some influence on the results of above-mentioned
activities, their arrangement and organization, Croatia is trying to find its own way by following the
international and European positive experiences with necessary tailoring to the specific Croatian situation
and with the main intension to make transition period as short, efficient and productive as can be
*
Predstavljeno na "Cambridge Conference 2003" održanoj u Cambridge-u, Engleska, 20.-25.7.2003.
godine. Objavljeno u zborniku radova Konferencije (Rožić, N.: Strategy and System of Quality Control of
the Official Geographic Data Produced by Private Companies in Croatia. Conference papers of the
Cambridge Conference 2003 "National mapping – shaping the future", Paper 7.3, Ordonance Survey,
England, 2003). Dostupno na CD-ROM mediju i Internet stranicama Konferencije www.cambridge
conference2003.com
- 41 -
achieved. As usual, "Croatian model", if one can speak about a model regarding the production of
geographical data, maps and some other products, is somewhere in the range between two extreme
alternatives, i.e. between the national wide mapping and geographical data producing like obligatory task
of the governmental bodies/organizations financed by government with taxpayers money and with the
data kept as a state secret and the mapping left completely to the market and private enterprises where
the government is only one of the potential customers in the market in accordance with the present and
near future state needs.
Regarding setting and general frame of "Croatian model", three basic "players" or groups of
"players" are in the game: State Geodetic Administration (SGA), Croatian Geodetic Institute (CGI) and
private companies registered and licensed to work in the field of the state survey and real estate
cadastre. Their competences and responsibilities, functions, fields of work and roles in joint and
coordinated production of national geographic data and building of National Spatial Data Infrastructure
are defined and determined precisely enough starting from visions and strategies, including planning,
financing and organizing over to the execution and finally fulfillment of the user needs.
2. GENERAL BASIS FOR OFFICIAL GEOGRAPHIC DATA PRODUCTION AND QC
Present situation in Croatia regarding general setting at the state level in respect with the official
geographic data production and quality control is a significant consequence of the new Law of State
Survey and Real Estate Cadastre (Official Newspaper 1999) proposed by the SGA and delivered by
Croatian Parliament and started to be implemented from the beginning of 1999.
2.1. STATE GEODETIC ADMINISTRATION
In accordance with the Law, the SGA being the basic state body responsible for geodetic and
surveying works and spatial data infrastructure at the whole state territory is reorganized, or is better to
say organized to be a unique and integral administration encompassing the Central Office in Zagreb and
all branch offices adequately distributed throughout the entire territory of Croatia (at this moment SGA
consists of about 110 branch offices with approximately 1100 employees). It has the authorities to do all
administrative, normative, regulative and standardizing jobs in connection with the state survey and real
estate cadastre. There has been a great change made in comparison with the previous period, i.e. before
1999. Namely, in the previous period the branch offices of SGA, i.e. former local cadastral offices, used
to be under the competence of local self-government units. In this respect, SGA is constituted pursuant
to the new Law as a unique and a coherent government body. It should also be emphasized that SGA
branch offices are still primarily related to the cadastral activities while SGA central office in Zagreb is
covering wide range of all other topics. In particular, especially great importance is given to the preparing
of laws, bylaws and ordonance basis, technical geodetic and surveying standards, preparation of the
annual or several years state survey and real estate programs and their realization and implementation.
In that respect, the internal structure and organization of SGA central office is adjusted to function
efficiently.
It should also be emphasized that SGA is not directly involved in production of geographic
(topographic) data and products based on these data internally. Production is planned and financed by
SGA but outsourced to the private sector, i.e. private companies licensed for production in accordance
with SGA product specifications. Planning and financing is based on adequate one year or several years
programs, at the present moment Program of State Survey and Real Estate Cadastre for the period
2001-2005 is just being carried out, proposed by SGA and approved by Croatian Parliament (Official
newspaper 2001). The example of some very important products in the field of responsibility of SGA,
according to the SGA official catalogue of products (State Geodetic Administration 2001), can be
presented as follows:
- Aerial photographs in the scale of 1:20000 from systematic cyclical photo shooting of the state
territory
- Orthophoto maps in the scale of 1:5000
- Croatian base maps in the scale of 1:5000
- Topographic maps in the scales of 1:25000, 1:100000, 1:200000, etc.
- Cadastral maps in the scales 1:1000, 1:2000, 1:2880, etc.
2.2. CROATIAN GEODETIC INSTITUTE
In addition to all structural, functional and other changes regarding SGA, one of very important
changes in terms of modernizing and reorganizing geodetic and surveying activities in Croatia is the
foundation of a separate and specialized public institution intended for performing scientific and highly
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professional geodetic works at the state level. This new institution, founded by the same Law, is Croatian
Geodetic Institute. Founder of the CGI is the Republic of Croatia and rights of founder are implemented
by the Government. In the Republic of Croatia there has never been such an institution. During the long
period of time, from the end of II. World War till the moment of CGI foundation, the practical realization of
high professional geodetic and surveying works (for example: state control networks of higher orders,
map series in the scale 1:25000, etc.) had been always under the competence of Military and
Geographic Institutes of the former states. As Law became operative, during 2000. concrete activities
were initiated in connection with the formation and establishment of CGI and have been continuously
performed ever since. With foundation of the CGI for the first time in the Republic of Croatia,
administrative, normative and regulative jobs in the field of geodesy at the state level are started to be
separated from professional jobs. CGI shoud be responsible for professional jobs and SGA should take
care of the administrative and normative jobs. CGI is formed as a specialized institution but without the
rights to be profitable or to compete with private companies at market. The work of CGI is regulated by
the Law of State Survey and Real Estate Cadastre, by the Law of Institutions and other positive laws and
regulations of the Republic of Croatia. Within its activity CGI should perform the following jobs:
- Conduct fundamental geodetic works
- Constitute topographic, cartographic and land registry databases
- Conduct topographic survey
- Constitute and keep geographic names register
- Conduct survey and marking of state border
- Conduct development and research projects
- Standardization of geodetic works and procedures.
Internal constitution of the CGI is based on the planned type and volume of geodetic works that it
should perform. The internal constitution is defined with four departments:
- Department for mutual jobs
- Department for fundamental geodetic works
- Department for topographic survey and supervising
- Department for geoinformation systems and databases.
Apart from the fact that CGI is constituted as an independent and specialized professional
institution for performing mentioned specific works, CGI is strongly connected with SGA and obliged to
jointly perform geodetic works and activities in accordance with the annual working programs
harmonized with the working programs of SGA at state level. In explained setting, accordingly to the
relations established between SGA and CGI, one very important function is directed to the CGI. That is
quality control function with the main purpose to provide and assure the quality and homogeneity of
geodetic products, i.e. official geographic (topographic) data produced for SGA (Croatian government) by
private companies. It should be pointed out that providing and approving the quality of the official
geographic data produced for the state has never been solved at the territory of Croatia in that way.
Additionally, it must be said that CGI's work on providing and controlling the quality has started to be
realized simultaneously with the foundation and building of CGI's overall infrastructure and capacities for
undertaking that work (equipment, education and specialization of personnel, defining of procedures and
methods, etc.). CGI's quality control function is strongly related and harmonized with the realization of the
Program of State Survey and Real Estate Cadastre for the period 2001-2005 (Official newspaper 2001).
Further more, in the same time the whole activity is strongly overlapping with quite recent activities of
implementation and realization of the important GI project prepared and organized in the frame of
technical and financial help given to the Republic Croatia by the Kingdom of Norway - CroatianNorwegian GeoInformation Project.
2.3. CROATIAN PRIVATE COMPANIES
In accordance with all transition changes that have happened in Croatia from 1990 untill today,
all geodetic and surveying companies have become private companies (private ownership). Some of
them which existed in period before 1990 were privatized but at the same time some companies were
initially founded after 1990.It should be said that several bigger companies with significant professional
potential and infrastructure for production of geographic (topographic) data have remarkable tradition and
experience because they were founded immediately after II. World War and they had been developed
during the period of almost 50 years. It is interesting that these companies are not exclusively
concentrated in Zagreb (capitol of the Republic of Croatia) but they are dispersed to the most bigger
Croatian cities spread over the country, for example: Split, Rijeka, Osijek, etc. Several bigger companies
were newly founded as well, after 1990, on the basis of the possibilities and conditions to develop private
enterprises. Some of them were founded by Croatian experts with work experience from abroad and they
were developed in quite fast and efficient way. It is important to point out that all those companies,
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privatized old ones and new ones, have very solid and recent technological infrastructure and level of
technical knowledge with experienced people involved in the production processes. They are fully
capable to produce specific products and geographical data for government needs in accordance with
SGA product specifications. In accordance with their development and continuous technological
modernization during last 10 years they gave a strong contribution to upgrading and improving of
specialized geodetic works at state level on the basis of appropriate coordination and collaboration with
SGA.
At this moment, for example production infrastructure for producing of Topographic maps in the
scale of 1:25000 has already been developed and usable in at least 6 private companies and all these
companies were actively included in their production during the last 6 years. Those companies are
competitors in public procurement procedures organized by SGA, regarding possibility of choosing the
best and most efficient (cost/benefit) production. Simultaneously with the mentioned production for
government needs, the private companies are completely free to produce other kinds of data or products
for other investors in accordance to their needs and apart from predefined product specifications maid by
SGA.
Apart from those bigger and "infrastructurally developed" private companies there are at the state
level also several hundreds (more than 400) of quite small private companies licensed to work in the field
of state survey and real estate cadastre. But all those companies (some of them are functioning only with
one or mybe two experts), founded practically after 1990, are related first of all to cadastre and real state
work or other specific kinds of work. Their production infrastructure, knowledge and production potentials
are not appropriate for the production of, for example, topographic maps, etc.
3. STRATEGY
As already mentioned in the introduction, two extreme alternatives (models) are possible if one
consider production of the geographical (topographic) data at the national (state) level, i.e.
- National wide mapping like strict obligation of the responsible governmental administration
organization financed by the government from the state budget and with data kept as a state
secret and
- Mapping left completely to the market and private enterprises where government is only one of
the potential customers in the market in accordance to the present and near future state needs.
As usual, these extreme alternatives are not strictly implementable because of several reasons
and besause each of them has important and significant disadvantages. Implementable "model" for each
country or state is somewhere in between of these extreme alternatives where some pragmatic reasons
must have influence on their mutual balance and adjustment to the general and specific state setting and
local conditions. Croatian answer to mentioned alternatives is a "model" defined on few following main
elements:
- Specific and standardized geodetic products (geographical data and information's), their
definition, specification, planning of production, financing, distribution to users (customers), etc.
are the responsibility of the appropriate state civil administration body, i.e. SGA. Produced data
or products have got no status of state secret data but copyright belongs to the state. Different
users, from private persons or companies to other government institutions have the possibility to
use and pay the usage of data or products for declared purpose in accordance with transparent
and acceptable SGA price list. Production is financed partly from the state budget (taxpayer's
money), partly by local municipalities or some other investors interested in specific product, for
example: Croatian Waters, Croatian Forests, etc. Main orientation in planning of production is
defined by user needs and SGA capability to achieve actuality and availability of products with
appropriate delivery time (that can be achieved in the frame of objective present Croatian
conditions).
- Production of previously mentioned specific and standardized products is completely directed to
the private companies specialized and infrastructurally capable for organizing and executing
efficient production with appropriate level of quality and homogeneity of products in accordance
with SGA product specifications. Production is connected with public and transparent
procurement procedures organized and conducted by SGA with main purpose to achieve most
efficient and productive results – guarantied quality of products in accordance with product
specifications produced for less money.
- Quality assurance and quality control of products produced by private companies is main
responsibility of CGI. In principle CGI is, apart a fact that is connected in work with SGA on same
programs, stand alone (independent) professional institution specialized for undertaking quality
control activities to assure quality and homogeneity of products. Line of responsibility between
SGA and CGI is very clear due to fact that SGA is administrative government body with
- 44 -
administrative and normative responsibilities and functions and CGI is professional one. Quality
control system is based on transparency, taking into account fact that best controllers of
products quality should be producers themselves, e.g. private companies.
Described "Croatian model" is a quite young model and his implementation is not completely
finished yet. Lots of activities are in realization simultaneously, first of all activities regarding building up
CGI's capacities and infrastructure to undertake QC work, coordination between SGA, CGI and private
companies, improvement of production regarding product specifications, procedures and methods,
introduction of new products, etc. So far achieved results are satisfactory and all recent activities are
showing that in Croatian circumstances and conditions "model" is giving expected benefits.
4. QUALITY CONTROL
Recognizing the most important elements of "Croatian model" and high motivation to improve
geodetic and surveying fields of work, especially with respect to Quality Control, the Kingdom of Norway
decided to give Croatia support and assistance for consulting services, efficient recent technologies
transfer, specialization, education and training of Croatian professionals and capacity building of CGI to
be able to significantly improve and implement QC work. In the mentioned setting, direct technical and
financial support, and assistance in planning, development and realization of a very important, significant
and complex project named Croatian-Norwegian GeoInformation Project -CRONO GIP, is given at the
end of 2001. CRONO GIP realization started in June 2002 and the expected end of project is December
2003
Within the frame of CRONO GIP, objectives, expected results and planned activities are in
accordance with fundamental strategic decision that CGI should be the main independent quality
controller of "geodetic products" produced by private geodetic and surveying companies at the state
level. In that sense, one should consider that the project activities at the moment are related to the three
main geodetic products, i.e. digital topographic (vector) data, TK25 and DOF.
The main objective:
- CGI shall be able to control the quality of geographic data (geodetic products) produced by
private companies for the Croatian Government
Expected results:
- CGI shall be able to perform satisfactory controlling of the quality of topographic (vector) data,
TK25 and DOF produced by private companies
- CGI shall be able to prepare draft regulations and standards in line with internationally accepted
standards, to be applied by private companies for assuring and documenting the production
quality.
Planned activities:
- Specification and verification of controlling procedures and related methods to be applied by CGI
taking due notice of internationally accepted standards and methods
- Verifying existing regulations and standards for quality assurance in production of geographic
data by comparing these to internationally accepted regulations and standards (ISO, CEN, etc.)
- Drafting new and improved regulations and standards (if found appropriate)
- Specification of the requirements concerning technical equipment, instruments and software
needed at CGI to be able to make relevant quality controls
- Procurement, installation and testing of instruments, hardware and software needed for quality
control
- Education, specialization and training in the use of the equipment and software
- Practical execution of controls on final products and relevant intermediate data resulting from
various steps within the production of TK25 and DOF
- Informing relevant users, private companies and public institutions about development of
regulations and standards and enhancing the awareness of international standards.
In the period from June 2002 till May 2003, intensive activities on the realization of CRONO GIP
have been carried out. Simultaneously with procurement of equipment for quality control, trainings of CGI
employees and verification of existing Croatian regulations, products specifications and standards,
crucial activity is connected with the development and defining of the CGI Quality System based on
internationally accepted standards adapted to the Croatian situation. The Quality System should be
based (Program Management and Mapping, 2002) on transparent set of documentation consisting of:
- General quality guidelines
- Producers (private companies) quality plan requirements
- Products specifications
- Control methods descriptions
- Specifications of sampling and tolerances for rejection and re-work of specific geodetic product
- 45 -
and should be developed and implemented in three hierarchical levels:
- I Level – Base documents describing overall principles of CGI's quality control work
- II Level – Base documents defining the products to be controlled, referring to the three basic
products: digital topographic (vector) data, TK25 (digital raster and paper form) and DOF
- III Level – Procedures and checklists necessary for undertaking all control work.
In addition to the three basic products involved in CGI's quality control activities additional
products (sub-products) are also included having in mind important intermediate steps in the production
processes: Aerial photo and ground control, Aerotriangulation, Scanned photo and Digital Terrain Model
(DTM). Important attention in realization of CGI's quality control system is given to the development of
new and the improvement of existing Product Specifications to insure appropriate and transparent quality
of production of the Topographic Data mapped and produced from aerial photos in the scale of 1:20000
including quality elements and sub-elements and tolerances like fundamental basis for quality control.
Precise and detailed Product Specifications are of great importance not only for CGI's control work but
for producers, users and government institutions as well.
Development and implementation of CGI's Quality System is still, till the end of May 2003, an ongoing
process with a lot of results and significant enhancements of existing CGI's capacities to undertake very
important activities regarding geodetic products quality control.
Till the moment of completing the work on this paper, all CRONO GIP activities have not been
concluded yet. In accordance with the general project setting they are in simultaneous realization with
specification and documentation development, trainings on job, definition of practical procedures and
methods for quality control are overlapping each other.
It should be emphasized that excellent collaboration of responsible institutions, companies and people
involved in the project realization exists at all levels, beginning with formal level of coordination between
SK, SGA and CGI to the level of professional work and collaboration between Norwegian and Croatian
consultants with SGA and CGI employees.
On the basis of so far achieved results it is realistic to expect that the capacities and capabilities of CGI
will be significantly enhanced and improved in a very limited time frame and that CGI will be able to
maintain and undertake all quality control works in the future with appropriate transparency and efficiency
for the benefit of all involved parties.
5. CONCLUSION
Implementation of the "Croatian model" regarding strategy and quality control of official
geographic data production is one of the examples how each country or state by following international
and European experiences tailored and customized to specific national conditions can build their own
specific solutions. That solution is still under development regarding implementation on practical every
day work level, connected with technology and knowledge transfer, education, training and
specialization, documentation development, coordination of involved parties, etc. It can be expected that
many of already unsolved or at least not efficiently solved elements will be improved in future period on
the basis of defined strategy and on the basis of clear and transparent policies.
REFERENCES
Official newspaper, 1999. The Law of State survay and Real Estate Cadastre. The Republic of Croatia,
No. 128/99, Zagreb, Croatia.
Official newspaper, 2001. Program of State Survey and Real Estate Cadastre for the Period 2001-2005.
The Republic of Croatia, No. 64/01, Zagreb, Croatia.
Program management and mapping, 2002. CRONO GIP Croatian Norwegian GeoInformation Project Inception study report, Croatiann Geodetic Institute, September 2002, Zagreb, Croatia.
State geodetic administration, 2001. Catalogue of products. Zagreb, Croatia.
Statens kartverk, 2001. Terms of reference for the implementation of component b) and c) of the
Norwegian assisted Project in Croatia for enhancing the capabilities of the Croatian Government
to build a National Spatial Data Infrastructure. Appendix A to the Contract, Oslo, December
2001, Norway.
Statens kartverk, 2002. Agreement for improving real estate information and geographic data
infrastructure in Croatia, Zagreb, December 2002, Croatia.
- 46 -
CAMBRIDGE CONFERENCE 2003
"NATIONAL MAPPING – SHAPING THE FUTURE"*
Željko Bačić, Nevio Rožić
Od 1928. godine, a motivirana prvim Internacionalnim geografskim kongresom (International
Geographic Congress) koji je okupio vodeće geodete tog vremena, započela se u Cambridge-u redovito
održavati i Imperijalna konferencija geodetskih dužnosnika (Empire Conference of Survey Officers) u
organizaciji Britanske kolonijalne komisije za izmjeru (British Colonial Survey Committee). Obzirom da je
konferencija bila vrlo produktivna i da je polučila zamjetne rezultate, ponovno je organizirana 1931.
godine, a nakon toga se u nizu, sve do posljednje održane 2003. godine, redovito održavala svake četiri
godine. Od 1995. godine profil i sadržaj konferencije bitno je izmijenjen, jer je postala internacionalno
mjesto okupljanja službenih predstavnika nacionalnih kartografskih organizacija, s izrazito naglašenim
sadržajima uzajamne razmjene znanja i iskustava, definiranja zajedničkih vizija i strategija, međusobnog
upoznavanja i stvaranja veza, diskusije, rasprave, razmjene mišljenja i realizacije zajedničkih ciljeva.
Obzirom da se tijekom dugog vremena tradicijski održava u Cambridge-u konferencija je dobila ime
"Cambridge Conference".
U razdoblju od 20. do 25. srpnja 2003. godine održala se sukladno prethodno objašnjenoj tradiciji
"Cambridge Conference 2003" čiji je sadržaj i područje interesa, više od 250 učesnika iz 76 zemalja sa
svih kontinenata, bila nacionalna kartografija kao temeljno sredstvo za oblikovanje budućnosti ("National
mapping – shaping the future"), obzirom na činjenicu da je u posljednjem vremenskom razdoblju svijest o
značaju i ulozi geografskih podataka i informacija u: definiranju razvoja, donošenju odluka na svim
razinama, planiranju, gospodarstvu, potrebama građana i drugim aktivnostima, postala nedvosmisleno i
opće prepoznatljiva. Konferencija se održala u prostorima St John's Colledge-a, Cambridge, u
organizaciji Ordnance Survey-a. Ispred organizatora voditelj konferencije bila je gospođa Vanessa
Lawrence, glavna i izvršna direktorica Ordnance Survey-a.
St John's Colledge-a, Cambridge
Treba naglasiti da je organizacija konferencije, kako u razdoblju priprema, tako i tijekom
održavanja, u svim elementima formalnog i neformalnog dijela bila besprijekorno učinkovita i kvalitetna.
Formalni sadržaj konferencije obuhvatio je niz tematski objedinjenih sesija i radionica s izrazito
naglašenom potrebom za "živom" raspravom i diskusijom, dok je neformalni dio bio obogaćen nizom
prigoda za neformalni razgovor, međusobno upoznavanje i razmjenu informa-cija. U sklopu svake od
tematskih sesija ili radionica znatno više vremena bilo je namijenjeno diskusijama nego izlaganju radova,
a izlaganja su bila sažeta i strogo vremenski ograničena. Stoga su i prije samog početka konferencije, a
u svrhu pravodobne pripreme za diskusije, svim učesnicima bili dostavljeni objedinjeni sadržaji i radovi
autora, sadržani na konferencijskom CD-ROMu te su istodobno bili postavljeni i na službene Internet
Objavljeno u Geodetskom listu 2003 godine (Rožić, N., Bačić, Ž.: Cambridge Conference 2003
"National mapping – shaping the future". Geodetski list, 2003, 3, 220-222).
*
- 47 -
stranice konferencije http://www.cambridgeconference2003.com/. Ujedno, radovi su objedinjeni i otisnuti
na klasičan način u zborniku radova konferencije.
U sklopu formalnog dijela konferencije održano je ukupno 9 sesija, od kojih su dvije sesije bile
namijenjene isključivo radionicama. Obzirom na vremenski raspored učesnici su, sukladno vlastitom
izboru i interesu, mogli sudjelovati najviše u radu dviju radionica unutar pojedine sesije. U nastavku se,
obzirom na opsežnost broja radova i autora, daje pregled sesija, voditelja sesija, tematsko određenje
radova u sesijama i radionicama te broj radova obuhvaćenih programom:
Prva sesija (21. srpnja 2003. godine). Voditeljica: Vanessa Lawrence (Director general and chief
executive, Ordnance Survey, Great Britain). U okviru sesije obavljeno je, uz iskazivanje dobrodošlice
učesnicima konferencije, službeno otvorenje i predstavljanje uvodnog rada konferencije pod nazivom
"Budućnost okosnice podataka: odmak od lista karte".
Druga sesija, 21. srpnja 2003. godine. Voditelj: Qassim Al Ghanim (Ministry of Municipal Affairs
and Agriculture, Qatar). Tema sesije bilo je značaj nacionalne kartografije u svijetu koji se neprekidno
mijenja. Predstavljena su četiri rada.
Treća sesija, 22. srpnja 2003. godine. Voditelj: Robin McLaren (Know Edge Ltd. UK). Sadržaj
sesije bio je objedinjen traženjem odgovora na simbolički postavljeno pitanje "Tko plaća kartografa?".
Predstavljeno je 6 radova.
Četvrta sesija, 22. srpnja 2003. godine. U sklopu sesije održane su četiri tematski i sadržajno
objedinjene radionice:
- tema prve radionice bila je pribavljanje političke podrške i financijskih sredstava za potrebe
nacionalne kartografije. Voditelj: Bryson Morebodi (Royal Institution of Chartered Surveyors,
UK). Predstavljena su 4 rada.
- tema druge radionice bilo je obrazovanje stručnjaka i kadrova za budućnost, u svjetlu intenzivnih
tehnoloških promjena. Voditelj: Jean Cooper (Natural Resources Canada). Predstavljena su tri
rada.
- tema treće radionice bila je tehnologija u okružju kartografije i prostornih podataka. Voditelj: John
Spital ( Land Information New Zeland). Predstavljena su četiri rada.
- tema četvrte radionice bila su pravna pitanja u svezi nacionalnih prostornih i kartografskih
podataka. Voditelj Alex Griffin (Ordnance Survey, GB). Predstavljena su četiri rada.
Peta sesija, 23. srpnja 2003. godine. U sklopu sesije održane su četiri tematski i sadržajno
objedinjene radionice:
- tema prve radionice bila je transformacija nacionalnih kartografskih organizacija u smislu
učinkovitog rada i funkcioniranja. Voditelj: Amithaba Pande (Department of Science and
Technology, India). Predstavljena su četiri rada.
- tema druge radionice bila je izgradnja nacionalnih infrastruktura prostornih podataka. Voditelj:
Peter Holland (Geoscience, Austria). Predstavljena su tri rada.
- tema treće radionice bilo je razumijevanje i prepoznavanje potreba korisnika te ukupnog vođenja
poslovanja i rada na ekonomskim osnovama. Voditelj: Derek Clarke (Surveys and Mapping,
South Africa). Predstavljena su četiri rada.
- tema četvrte radionice bio je utjecaj tehnologija na razvoj specifičnih aplikacija vezanih uz
prostorne podatke. Voditelj: Zeljko Bačić (Državna geodetska uprava, Hrvatska). Predstavljena
su četiri rada.
Šesta sesija, 23. srpanj 2003. godine. Voditelj: Santiago Borrero (Institute for Pan American
Geography and History, Columbia). Sadržaj sesije odnosio se na opće okružje i kontekst infrastrukture
prostornih podataka. Predstavljena su četiri rada.
Sedma sesija, 24. srpanj 2003. godine. Voditelj: Barbara Ryan (US Geographical Survey, US).
Sadržaj sesije odnosio se na interakciju i upošljavanje privatnog sektora u proizvodnji nacionalnih
prostornih i kartografskih podataka. Predstavljeno je 6 radova.
Osma sesija, 24. srpanj 2003. godine. Voditelj: Joakim Ollen (National Land Survey of Sweden).
Sadržaj sesije bilo je predviđanje budućih trendova i procesa vezanih uz utjecaj tehnologije na aktivnosti
nacionalnih kartografskih organizacija. Predstavljeno je šest radova.
Deveta sesija, 24. srpanj 2003. godine. Voditelj: Vanessa Lawrence (Director general and chief
executive, Ordnance Survey, Great Britain). U sklopu sesije donesene su rezolucije konferencije,
dogovorene i prihvaćene određene aktivnosti koje će se obaviti do naredne konferencije te je
konferencija službeno okončala svoj rad.
U sklopu neformalnog dijela konferencije bio je organiziran opsežan i relativno raznolik program
koji je obuhvatio:
- održavanje izložbe "The Great Arc of India", posvećenoj izmjeri indijskog potkontinenta,
- prikazivanje prigodnog filma posvećenog tijeku i sadržaju izmjere indijskog potkontinenta,
- održavanje specijalizirane izložbe proizvoditelja informatičke i geodetske opreme,
- održavanje prigodnog konferencijskog predavanja "Hotine lecture" kojeg je održao profesor
- 48 -
Gordon Convay, predsjednik Rockefeller fondacije,
posjet institucijama: Ordnance Survey u Southamptonu, Land Registry, Royal Geographical
Sociaty i Defence Geographic and Imaginery Agency u Londonu,
- posjet instituciji Royal Institution of Chartered Surveyors u Londonu.
U radu konferencije bila je zastupljena i Republika Hrvatska, predstavnicima Državne geodetske
uprave Republike Hrvatske u svojstvu nacionalne kartografske organizacije (nadležnost za nacionalne
prostorne podatke i kartografske proizvode) i Hrvatskoga geodetskog instituta. Tako su u sklopu sedme
sesije konferencije predstavljena dva uzajamno povezana rada:
- Baćić, Ž., "Outsourcing whole production out of NMO: Croatia as an example",
- Rožić, N., "Strategy and System of Quality Control of the Official Geographic Data produced by
Private Companies in Croatia".
-
Prezentacija Ž. Bačića
Prezentacija N. Rožića
Citirani radovi pružili su učesnicima konferencije uvid u strategiju, način i rezultate procesa
sustavnog uključivanja privatnog sektora (geodetske tvrtke) u proizvodnju prostornih podataka i
kartografskih proizvoda za nacionalne potrebe. Model koji se primjenjuje u Hrvatskoj specifičan je u nizu
elemenata u odnosu na iskustva i praksu europskih i drugih država te je izazvao zamjetan interes i
diskusiju učesnika konferencije. U okviru diskusije, a nakon prezentacija, za predstavljeni su model
učesnici konferencije učestalo koristili naziv "Hrvatski model", što posredno ukazuje kako na njegovu
specifičnost, tako na interes i pozornost koji su mu pridodali učesnici konferencije. Također, zanimljivo je
naglasiti i činjenicu da je jedan od zaključaka sadržanih u citiranim radovima i prezentacijama, u
djelomice redefiniranom obliku, postao i sastavni dio rezolucije konferencije, tj. precizirao je određenje da
svaka od država sljedeći zajedničku viziju izgradnje nacionalne strukture prostornih podataka i
proizvodnje kartografskih proizvoda ima, ne samo mogućnost već i puno pravo izgrađivati i slijediti svoj
vlastiti model. Sukladno tomu, može se ocijeniti da su se radovi, sadržajno i tematski te svojom razradom
učinkovito, aktualno, koherentno i meritorno uklopili u okvir i sadržaj konferencije te tako pridonijeli
afirmaciji Republike Hrvatske i njenih institucija.
- 49 -
- 50 -
CROATIAN-NORWEGIAN GEOINFORMATION PROJECT*
Nevio Rožić, Slavko Lemajić, Mladen Rapaić
ABSTRACT
Recognising specific needs of the Republic of Croatia in transition period and high motivation of
responsible Croatian state institutions to improve geodetic and surveying professional activities at state
level, the Kingdom of Norway decided to give Croatia support and assistance for consulting services,
efficient technology transfer, specialisation, education, training of Croatian professionals and capacity
building of Croatian institutions to be able to significantly improve their work. In the mentioned setting,
direct technical-financial support and assistance in planning, development and realization of a very
important, significant and complex project named Croatian-Norwegian GeoInformation Project (CRONO
GIP) is given. On the basis of efficient collaboration between Norwegian Mapping Authority (Statens
Kartverk), Program Management and Mapping consultant company on the Norwegian side and State
Geodetic Administration and Croatian Geodetic Institute on the Croatian side, CRONO GIP started to
be realized during June 2002. Regarding the Croatian Geodetic Institute participation in project
realization, the main objectives are establishment and implementation of the Quality Control System
which will assure efficient, transparent and professional quality control of some specific geodetic
products: topographic (vector) data, topographic maps in the scale of 1:25000 and orthophoto maps in
the scale of 1:5000, produced for the Croatian Government by private companies. Objectives, expected
results and CRONO GIP activities are definded and specified in accordance with the fundamental idea
that Croatian Geodetic Institute has become, apart from the fact that has been recently founded and
established government institution, the main quality controller of mentioned geodetic products.
KEYWORDS
Croatian-Norwegian collaboration, Technology transfer, Education
Geoinformation project, Quality control, Croatian Geodetic Institute
and
training,
1. INTRODUCTION
After acquiring the independence and sovereignty at the beginning of the 90-ties and after
suffering from war until 1995, the Republic of Croatia initiated significant and extensive activities in the
field of geodetic and surveying works at the state level. In completely new circumstances, Croatia has
been forced in a very short period to reorganize and establish their own government institutions
responsible for geodetic and surveying works important for state at the whole state territory, to define and
improve appropriate legal fundament for geodetic and surveying activities, to motivate and improve
production in private companies, etc. Among all activities, special importance is given to building and
development of the National Spatial Data Infrastructure and systematic production of digital (vector)
topographic data, renewal and production of topographic map series and orthophoto maps for the whole
state territory, renewal and technological modernization of cadastre and land registry in the sense of
efficient market economy and protection of private ownership.
Some of very important elements and results regarding mentioned activities achieved after 1995
are:
- From the beginning of 1999, the new Law of State Survey and Real Estate Cadastre delivered
by Croatian Parliament is valid and a set of new important bylaws has been delivered
- State Geodetic Administration (SGA) as the main government administration body responsible
for geodetic and surveying works at the whole state territory is reorganised and modernized
- Croatian Geodetic Institute (CGI) like completely new government institution for specialized
geodetic and surveying works is founded and started to work
- Program of State Survey and Real Estate Cadastre for the period 2001-2005 is delivered by
Croatian Parliament and started to be implemented
Predstavljeno na International Society for Photogrammetry and Remote Sensing (ISPRS) WG VI/3
Workshop-u: "GeoInformation for Practice", održanom u Zagrebu 15.-18.10.2003. godine. Objavljeno u
zborniku radova (Rožić, N., Lemajić, S., Rapaić, M.: Croatian-Norwegian Geoinformation Project.
Proceedings of the International Society for Photogrammetry and Remote Sensing (ISPRS) WG VI/3
Workshop: "Geo-Information for Practice", 15-18 October 2003, ISSN 1682-1750, Zagreb, Croatia, 224227).
*
- 51 -
Production of new topographic map series in scale 1:25000 (TK25) and orthophoto maps in
scale 1:5000 (DOF) covering state territory is started, including production of topographic
(vector) data, etc.
Apart fact that Croatia has much more than hundred years old tradition in carrying out geodetic
and surveying works lot of disadvantages are connected with fast and efficient improvement of existing
situation and realization of planned activities at state level. Some of them are:
- Quite complicated and to Croatia not completely appropriate geodetic and surveying heritage
from the former Yugoslavia
- Very fast and complex state transition period overlapping with war situation, including all
economic and financial consequences
- Very fast worldwide changes in technology, production infrastructure, HW&SW solutions and
specialised knowledge in field of production and distribution of geoinformations and geodata, etc.
- Limited state resources (state budget, level of organization, infrastructure resources, etc.) for
autonomous fast and efficient solving of quite complex tasks like for example development of the
National Spatial Data Infrastructure, etc.
- Lack of experience and recent knowledge regarding some specific fields of professional work, for
example Quality Control (QC) of "geodetic products" or more widely, the geodata especially
related to the international and European standards (ISO, CEN), etc.
Recognising most important elements of Croatian situation and high motivation to improve
geodetic and surveying fields of work, some European countries decided to give Croatia support and
assistance for consulting services, efficient recent technologies transfer, specialisation, education and
training of Croatian professionals and capacity building of Croatian responsible institutions to be able to
significantly improve their work. In the mentioned setting, the Kingdom of Norway decided to give to the
Republic of Croatia and responsible Croatian institutions direct technical and financial support, and
assistance in planning, development and realization of a very important, significant and complex project
named Croatian-Norwegian GeoInformation Project (CRONO GIP).
Apart from having great significance and meaning for the whole state CRONO GIP has got at
same time enormous significance for SGA and CGI's development. It should be pointed out that CGI is a
completely new institution in Croatia, recently founded and functioning from December 2001. The
assistance to CGI in building and developing capacities for specialised professional works, including
technology transfer, specialization, education, training, infrastructure building (equipment), etc. is the
basis for efficient improvement and enhancement of CGI's existing work and possibility to upgrade joint
work of SGA, CGI and private companies within the frame of realizing the Program of State Survey and
Real Estate Cadastre for the period 2001-2005.
-
2. CRONO GIP CONTENT
Norwegian assistance to Croatia has been initiated by request of the Government of the
Republic of Croatia to the Norwegian Ministry of Foreign Affairs. Norwegian Mapping Authority – Statens
Kartverk (SK) has been contracted to act on behalf of Norway in the process of planning and
implementation of CRONO GIP, together with SGA and CGI on Croatian side. During December 2001
the initial Agreement between SK, SGA and CGI was signed in Oslo for the implementation of the project
for enhancing the capabilities of the Croatian Government to build a National Spatial Data Infrastructure.
After tendering procedure executed in Norway consultant company, Program Management and Mapping
(PMM) has been selected to carry out the consultancy work and in the same time some consultants from
Croatian private companies were included in PMM consultant team. CRONO GIP has formally started to
be realized during June 2002. On the basis of CRONO GIP, the realization of additional extension of the
project has been defined at the end of 2002. During December 2002 the second Agreement between SK,
SGA and CGI has been signed in Zagreb regarding significant content extension with respect to the
initial CRONO GIP agreement. Because of that one can recognize the realization of two very strongly
connected projects CRONO GIP I and CRONO GIP II.
The main areas of CRONO GIP I activities (Statens Kartverk, 2001):
- Establishment of the capacity within SGA to scan and vectorise existing paper maps (cadastral
maps, Croatian basic maps in scale 1:5000, etc.)
- Development and implementation of a database within SGA for storage and use of data resulting
from the on-going production of new topographic maps in the scale 1:25000
- Establishment of a capacity within CGI to control the quality of geographic data produced for the
Croatian Government by private companies.
Main areas of CRONO GIP II activities (Statens Kartverk, 2002):
- Production of digital cadastral maps within SGA to enhance the capacity developed by CRONO
GIP I
- 52 -
Scanning and vectorisation of existing topographic maps in the scale 1:5000 within SGA
Enhancement of capacity of CGI to control quality of geodetic works
Establishment of a pilot geographic information system for the Croatian national park of Kornati.
In the following chapters special attention will be given to CRONO GIP I activities directly
connected with CGI, apart from the fact that SGA and CGI are strongly dependant and mutually involved
in the project realization.
-
2.1. CRONO GIP OBJECTIVES, EXPECTED RESULTS AND ACTIVITIES RELATED TO THE CGI
Within the frame of CRONO GIP I, objectives, expected results and planned activities are in
accordance with fundamental strategic decision that CGI should be the main quality controller of
"geodetic products" produced by private geodetic and surveying companies at the state level. In that
sense, one should consider that the project activities are related to the three main geodetic products, i.e.
digital topographic (vector) data, TK25 and DOF.
Main objective:
- CGI shall be able to control the quality of geographic data (geodetic products) produced by
private companies for the Croatian Government
Expected results:
- CGI shall be able to perform satisfactory controlling of the quality of topographic (vector) data,
TK25 and DOF produced by private companies
- CGI shall be able to prepare draft regulations and standards in line with internationally accepted
standards, to be applied by private companies for assuring and documenting the production
quality.
Planned activities:
- Specification and verification of controlling procedures and related methods to be applied by CGI
taking due notice of internationally accepted standards and methods
- Verifying existing regulations and standards for quality assurance in production of geographic
data by comparing these to internationally accepted regulations and standards (ISO, CEN, etc.)
- Drafting new and improved regulations and standards (if found appropriate)
- Specification of the requirements concerning technical equipment, instruments and software
needed at CGI to be able to make relevant quality controls
- Procurement, installation and testing of instruments, hardware and software needed for quality
control
- Education, specialization and training in the use of the equipment and software
- Practical execution of controls on final products and relevant intermediate data resulting from
various steps within the production of TK25 and DOF
- Informing relevant users, private companies and public institutions about development of
regulations and standards and enhancing the awareness of international standards.
CRONO GIP I realization started in June 2002 and the expected end of project is December
2003 including CRONO GIP II extension regarding CGI quality control activity. It should also be
mentioned that apart from financing the consultancy services, the Norwegian funding within the frame of
CRONO GIP I covers the amount of 600.000,00 NOK for procurement of equipment (hardware and
software) and training with additional CGI participation in project with 400.000,00 NOK. In similar way,
within the frame of CRONO GIP II, the additional amount of 310.000,00 NOK from Norwegian side and
500.000,00 NOK from Croatian side are set aside.
3. REALIZATION OF CRONO GIP I
In the period from June 2002 till May 2003, intensive activities on the realization of CRONO GIP I
have been carried out. Simultanesously with procurement of equipment for quality control, trainings of
CGI employees and verification of existing Croatian regulations, products specifications and standards,
crucial activity is connected with the development and defining of the CGI Quality System based on
internationally accepted standards adapted to the Croatian situation. The Quality System should be
based (Program Management and Mapping, 2002) on transparent set of documentation consisting of:
- General quality guidelines
- Producers (private companies) quality plan require-ments
- Products specifications
- Control methods descriptions
- Specifications of sampling and tolerances for rejection and re-work of specific geodetic product
and should be developed and implemented in three hierarchical levels:
- I Level – Base documents describing overall princip-les of CGI's quality control work
- 53 -
II Level – Base documents defining the products to be controlled, referring to the three basic
products: digital topographic (vector) data, TK25 (digital raster and paper form) and DOF
- III Level – Procedures and checklists necessary for undertaking all control work.
In addition to the three basic products involved in CGI's quality control activities additional
products (sub-products) are also included having in mind important intermediate steps in the production
processes: Aerial photo and ground control, Aerotriangulation, Scanned photo and Digital Terrain Model
(DTM). Important attention in realization of CGI's quality control system is given to the development of
new and the improvement of existing Product Specifications to insure appropriate and transparent quality
of production of the Topographic Data mapped and produced from aerial photos in the scale of 1:20000
including quality elements and sub-elements and tolerances like fundamental basis for quality control.
Precise and detailed Product Specifications are of great importance not only for CGI's control work but
for producers, users and government institutions as well.
Development and implementation of CGI's Quality System is still, till the end of May 2003, an
ongoing process with a lot of results and significant enhancements of existing CGI's capacities to
undertake very important activities regarding geodetic products quality control.
-
3.1. EQUIPMENT AND TRAININGS
Within the frame of CRONO GIP I, the realization set of quite important activities consists of
specification, procurement, testing and implementation of the technical equipment, hardware and
software needed at CGI to be able to make relevant quality controls paralel with specialization, education
and training of CGI's employees to efficiently use technical equipment. These activities will be almost
fully finished till the end of May 2003 except the training at photogrammetric digital station and practical
control training on final geodetic products.
With respect to the equipment, with already existing CGI equipment infrastructure, following items are
procured and they started to be used in every day work:
- Digital photogrammetric station hardware with appropriate photogrammetric software
- GPS hardware and software
- CAD and GIS software
- DTM software
- Plotting and presentation hardware.
Education and training of CGI employees regarding procured equipment and the whole content
of CRONO GIP I activities was organised and already almost concluded at two levels. The first level was
realized within the frame of hardware/software vendor trainings:
- Feature Manipulation Engine (FME)
- Oracle Spatial
- GPS hardware and software,
while the second level was realized within the frame of direct consultations during the organized
trainings:
- Microstation
- Geomedia
- Scope, etc.
with lots of elements of general and specific knowledge transfer in the fields of organization,
management and execution of specific tasks.
Like very illustrative example of training efficiency and overall knowledge transfer, regarding the
fact that specialised works has never be done in CGI before CRONO GIP realization, the quality control
of upgraded and topologically cleaned digital topographical (vector) data produced by six Croatian
private companies has been carried out with remarkable success.
3.2. FURTHER ACTIVITIES
Till the moment of completing the work on this paper, all CRONO GIP activities have not been
concluded yet. In accordance within general project setting they are in simultaneous realization with
specification and documentation development, trainings on job, definition of practical procedures and
methods for quality control are overlapping each other.
It should be emphasised that excellent collaboration of responsible institutions, companies and
people involved in the project realization exists at all levels, beginning with formal level of coordination
between SK, SGA and CGI to the level of professional work and collaboration between Norwegian and
Croatian consultants with SGA and CGI employees.
On the basis of so far achieved results it is realistic to expect that capacities and capabilities of
CGI will be significantly enhanced and improved in a very limited time frame and that CGI will be able to
- 54 -
maintain and undertake all quality control works in future time with appropriate transparency and
efficiency for the benefit of all involved parties.
4. CONCLUSION
CRONO GIP is one of very good examples of internationally planned and executed professional
projects containing elements of technology and knowledge transfer, education, training and
specialization in specific field of professional work. Efficiency of realization is based on several important
elements, i.e.:
- Very clear and precise definition of project objectives, expected results and activities (Terms of
Reference) with precise and strict planning, management and project execution
- Excellent coordination between responsible institutions, companies and state bodies involved in
realization,
- Excellent and fruitful collaboration between Norwegian consultants, Croatian experts and
SGA/CGI employees,
- High level of motivation of Croatian institutions to improve and upgrade their own professional
activities following recent international and European experiences and technological
development
- Appropriate technical level and knowledge on Croatian side like basis for "easy", logical and
sustainable organizational and professional upgrade and improvement
- Partially Croatian financial funding of project realization, etc.
Additionally, if one considers the impact of CRONO GIP realization on CGI as a very young and
still not completely developed Croatian professional institution, great benefit can be recognized in full
extent from the work in multi-language environment to the technological and other integration into the
geodetic space of the united Europe. In that sense, the specialization and education of CGI's employees,
qualified engineers of geodesy already is and will be of great importance for all future works.
After all, technical and financial help of the Kingdom of Norway, through realization of CRONO
GIP, will significantly improve and speed up specific professional activities in the Republic of Croatia as
one of the central European transition countries.
REFERENCES
Program Management and Mapping, 2002. CRONO GIP Croatian Norwegian GeoInformation Project Inception study report, Zagreb, Croatia.
Statens Kartverk, 2001. Terms of reference for the implementation of component b) and c) of the
to build a National Spatial Data Infrastructure. Appendix A to the Contract, Oslo, Norway.
Statens Kartverk, 2002. Agreement for improving real estate information and geographic data
infrastructure in Croatia, Zagreb, Croatia.
ACKNOWLEDGEMENTS
Croatian Geodetic Institute wishes to acknowledge his great appreciation and gratitude to all
Norwegian official state and professional institutions, companies and people for their assistance and
support which have contributed in one way or another towards the successful planning, implementation,
tracking and realization of the Croatian-Norwegian GeoInformation Project. CGI especially wishes to
acknowledge his appreciation, gratitude and thanks to the Ambassador of Norway in Zagreb, His
Excellency Mr. Knut Tørrasen and to the officials of the Norwegian Mapping Authority: Director General
Mr. Knut O. Flåthen, Senior Adviser Mr. Helge Onsrud and Senior Engineer Mr. Kjell E. Aadnevik. Finally
CGI wishes to express its deepest thanks to CRONO GIP team leader Mr. Jostein Sageie and the whole
PMM consultant's team for all fruitful discussions, recommendations, guidance and efforts invested in the
realization of the project.
- 55 -
- 56 -
IMPROVEMENT OF QUALITY CONTROL SYSTEM IN CROATIA*
Slavko Lemajić, Nevio Rožić, Mladen Rapaić
ABSTRACT
Croatian Geodetic Institute (CGI) was founded in February 2001 and started with professional
work at December of 2001. CGI is an independent institution but working closely with State Geodetic
Administration (SGA). According to Law on State Survey and Real Estate Cadastre (Croatian Parliament,
1999) CGI is responsible for scientific geodetic and surveying works and for quality control of geodetic
products produced by geodetic companies. At the beginning of professional work CGI started with
performing of digital orthophoto control and analogue topographic maps control. At that time the CGI
quality system was not in accordance with ISO standards. The Book of Ordinance (State Geodetic
Administration, 2001) was the key document for ensuring quality control. Lack of software systems and
hardware infrastructure, supporting data necessary for quality control, procedures and formal QC
documentation were the main reason to start establishment and development of new CGI Quality System
for quality control of geodetic products. Croatian-Norwegian Geoinformation Project (CRONO GIP)
started in June 2002. Implementation of component c) of the Norwegian assisted Project in Croatia for
enhancing the capabilities of the Croatian Government to build a National Spatial Data Infrastructure has
according to Terms of reference (Statens Kartverk, 2001) three objectives: CGI shall be able to control
the quality of topographic data produced by geodetic companies for SGA, CGI shall be able to perform
satisfactory controlling of the quality of topographic maps and orthophotos produced by geodetic
companies and CGI shall be able to prepare draft regulations and standards in line with international
standards, to be applied by geodetic companies for assuring and documenting quality in the production
of geographic data. Before Implementation of CRONO GIP results, CGI performed the Test Quality
Control. The Dataset, which was the subject of Control, CGI have controlled according to Specification
which are made for Data Upgrade. The Results with Reports of Test Control are delivered to Producers
for corrections. After Corrections the Structure of Dataset was acceptable for further methods of control.
KEYWORDS
Geoinformation project, Data upgrade, Quality control, Quality Plan, Croatian Geodetic
Institute, ISO
1. INTRODUCTION
At the end of 2001 CGI started with professional work in the field of control of orthophoto in the
scale 1:5000 and control of topographic map in the scale 1:25000. The control of these products was not
based on ISO rules. Lack of experience, equipment and specifications which were needed for control,
demanded to make full control of these products. Also, before establishment of CGI there was no
institutional system for making quality control but CGI started with improvement of the quality of products.
CRONO GIP which started in June 2002 had a main goal to improve quality control system in
CGI. Consultant Team made Inception study report (Program Management and Mapping - PMM, 2002)
for producing detailed project plan, for reviewing all activities defined in Terms of Reference, for verifying
the project objectives and local awareness for the Project, setting guidelines and procedures for
execution and building the team.
The base activity of CRONO GIP which is connected with Croatian Geodetic Institute is to
establish capacity in CGI to control the quality of geodetic data produced by geodetic companies for
State Geodetic Administration. From the beginning, the planned activities if the Project are:
- Specification and verification of controlling procedures and methods for CGI according to ISO
- Verification of existing documentation with comparing to ISO standards
- Drafting new regulations and standards
- Specification and procurement of equipment (hardware and software)
- Education in the use of new equipment (training)
zborniku radova (Lemajić, S., Rožić, N., Rapaić, M.: Improvement of Quality Control System in Croatia.
Proceedings of the International Society for Photogrammetry and Remote Sensing (ISPRS) WG VI/3
Workshop: "GeoInformation for Practice", 15-18 October 2003, ISSN 1682-1750, Zagreb, Croatia, 168172).
*
- 57 -
- Practical execution of controls on products and making the reports.
The realization of the Project is based on a set of documentations:
- Products and product specifications
- Quality plan
- Procedures and checklists
- Reporting.
1.1. PRODUCTS
Product is a set of work results, which can be used for several purposes. The Product is defined
by Product Specifications. For each Product, requirements are set to the Process leading up to the final
product. These processes are subject to Process Specifications. The process specification will mainly be
required to process documentation. The Process Specifications are subject to more frequent changes
due to development of technology and methodology, compared to the product specifications that are of a
more permanent character.
Product Specifications and Process Specifications are related to Quality Elements and Quality
Sub elements ISO/DIS 19113 and ISO/DIN 19114 (International Organization for Standardization, 2001
and 2002). Each of these elements is described with:
- Definition of the quality element/sub element
- Specification
- Producers documentation requirements.
The control of these elements is described with respect to:
- Sampling strategy
- Accept/reject rules
- Quality control method.
Following products are defined:
- Aerial Photography and Ground Control Points
- Scanned Photo
- Aerial Triangulation
- Topographic Data
- Digital Terrain Model (DTM)
- Topographic map in scale 1:25000 (TK25)
- Digital orthophoto in scale 1:5000 (DOF).
1.2. QUALITY PLAN
Quality Plan defines the organization, policies and procedures applied by CGI when undertaking
quality control of product deliverables. Developing and inspection plan and execution describes how
individual inspections are planned and undertaken. Inspection of a product may consist of many
individual inspections.
Developing of inspection plan describes the steps to follow when developing an Inspection Plan.
The result of this examination shall be written in the Inspection Plan for the Project. The same Inspection
Plan template can be used over again for new projects of similar nature.
Execution shows the steps to follow when undertaking the Inspection Work. The inspection itself
must be new for each project however the procedure can be the same for similar projects.
a) The development of a control plan follows the next six steps:
- Identification of dataset - when identifying the dataset, the relevance of the data should be
emphasized.
- Identification of data quality elements - the control might involve one or more quality elements.
The control plan will identify all data quality elements and data quality sub elements relevant for
the product or service.
- Identification of data quality measure - the data quality measure has to be defined.
- Identification of tolerances - requirements for geographic information specified as tolerance are
standard parts of the specifications for the data set.
- Identification of data quality scope - the geographic area for the control and groups of objects
has to be identified. A choice has to be done between full inspection and sampling. If sampling is
chosen, the size of the scope and geographic location has to be identified.
- Identification of control method - the control method has to be defined.
b) Execution of inspection contains the following:
- Undertake control measurements and calculate Values for data quality measures.
True values must be obtained, usually by control measurements. Corresponding values are
- 58 -
selected from the dataset. The difference between the value of the dataset and the true value is
the discrepancy. Based on all differences, the value for the current quality measure can be
evaluated.
- Compare calculated values for quality measures with tolerances.
Values from the control measurements shall be compared with the tolerance of the data quality
measure. It has to be decided whether the quality corresponds with the product specifications or
not. The result must be significantly worse than the tolerance before the dataset is rejected.
- Approval and handling of gross errors/discrepancies.
When the control is finished, it has to be decided whether the dataset shall be approved, rejected
or if the control shall be expanded.
- Reporting.
Reporting can be done in two ways:
- Prepare a special inspection report
- Report as metadata.
It is recommended to report by means of inspection reports.
1.3. PROCEDURES AND CHECKLISTS
A Checklist is a Formal description of a task mainly built up of boxes to be filled in, ticked or
signed.
All Procedures and Checklists are controlled by a system of sponsor and custodian where both
signatures are required before the documents are released for use. Custodians are responsible for the
distribution and revision control of all documents assigned to them. Sponsors authorize the content of the
document for use. As a general rule, sponsors are departmental managers.
Data quality methods are divided into two main classes, direct and indirect. Direct methods
determine data quality through the comparison of the data with internal and/or external reference
information. Indirect methods infer or estimate data quality using information on the data such as lineage.
The direct evaluation methods are further sub classified by the source of the information needed to
perform the evaluation.
a) Direct Evaluation Methods
- Types of Direct Evaluation Methods: internal and external.
- Means of Accomplishing Direct Evaluation: for both external and internal evaluation methods,
there are two considerations, automated or non-automated and full inspection or sampling.
- Full inspection
- Sampling
b) Indirect Evaluation Method
The indirect evaluation method is a method of evaluating the quality of a dataset based on
external knowledge. This external knowledge may include, but is not limited to, data quality overview
elements and other quality reports on the dataset or data used to produce the dataset.
1.4. REPORTING
Reporting of Data Quality Evaluation Information is possible as:
- Reporting in Metadata
- Reporting in a Quality Evaluation Report
- Reporting Aggregated Data Quality Result.
It is recommended to report by means of Inspection Reports.
2. TEST QUALITY CONTROL OF TOPOGRAPHIC DATA
Before the end of Project CGI has preformed test quality control of topographic data. Preliminary
tasks that are done can be described as:
- Verification of existing data according to CROTIS (State Geodetic Administration, 2002)
- Data upgrade specification (PMM, 2003)
- Quality control of upgraded data.
2.1. VERIFICATION OF EXISTING DATA
For verification of existing data six Croatian private companies delivered a part of data from
dataset that were the object for comparison with Croatian Topographic Information System (CROTIS)
data model. Another objective was how to bring the existing data up to new Specification. The task was
- 59 -
to determinate differences between datasets and existing specification. It resulted in the the report about
the existing data based on examples of six companies. Findings were divided on:
- Global remarks to existing specification (or incomplete specification)
- Global remarks to all companies
- Specific remarks for a single company.
2.2. DATA UPGRADE SPECIFICATION
Data upgrade specification describes:
- Content of specification
- Terminology used in specification
- Deliverables
- Specification for geometry and topology
- Specification for topographic data
- DTM specification.
According to this Specification companies have upgraded the Data. The main activity in pre
qualification process was changing attributes and topological cleaning the data. Such prepared data will
be ready for input into database.
The integral parts of specifications are:
- Object selection criteria
- Mapping catalogue
- Library of symbols
- Quality elements.
In the specification, there is also the terminology described that is partly based on Simple
Feature Specification by Open GIS Consortium.
According to specification, the contractors should deliver final production report and the dataset.
Final production report contains Production metadata and other information, Descriptions of topology
processing procedures and Descriptions of quality control procedures for important processes. Dataset
to be delivered is Topographic vector data in 2D and Digital terrain model (DTM) vector data in 3D. All
data should be delivered in „dgn” format (Microstation). Coordinate system of dataset, file names ad
media are described too. Specification for geometry and topology describes that delivered data should
contain only line string and point geometries. Data topology describes that polygons are not allowed but
polygons should be automatically generated from the data. The same rule with requirements for topology
is described. Specification of topographic data describes groups of feature classes and representation in
„dgn” files. Representation of feature classes is described in „Mapping catalogue” and selection criteria in
„Selection criteria” for data capture. Distribution of feature classes is divided by groups, levels and files.
The specification also describes which feature classes and in what way they should be represented.
There are following feature classes: Toponyms, Buildings, Utility, Transportation and elevated features,
Vegetation, Hydrographic and digitized feature. DTM Data Specification contains Digital Terrain model
and DTM data processing procedures. DTM features are spot heights, mass points, break lines, form
lines and areas of unreliable DTM. In DTM data processing procedures are data preparation, data
vectorization, data editing, data specification, quality control and delivery formats.
2.3. DATA UPGRADE QUALITY CONTROL
State Geodetic Administration (SGA) contracted data upgrade for six map sheets of Topographic
map in scale of 1:25000 (TK25) with six geodetic companies. They upgraded existing dataset according
to Data Upgrade Specification and Mapping Catalogue. Before starting the job consultant team of
CRONO GIP made training for geodetic companies. Companies delivered upgraded data with technical
reports.
CGI, in coordination with CRONO GIP Team, made a strategy for quality control. The Strategy
contained:
- Quality Plan
- Quality methods with realization
- Results of control
- Reports.
2.3.1. QUALITY PLAN
Quality Plan defines requirements for quality control of upgraded data and Quality Management
System. Quality system in this Quality Plan covered Product of Topographic Data. Quality Plan covered
- 60 -
following steps:
- Control of deliverables
- Control according sources
- Control of structure of data
- Control of topology
- Control of DTM dataset.
Geodetic companies delivered mainly the following files:
- YYYY-MM-DD-<ContractorID>-<MapNumber>-BUILDINGS.dgn
- YYYY-MM-DD-<ContractorID>-<MapNumber>-UTILITY.dgn
- YYYY-MM-DD-<ContractorID>-<MapNumber>-LANDCOVER.dgn
- YYYY-MM-DD-<ContractorID>-<MapNumber>-DIGITISED.dgn
- YYYY-MM-DD-<ContractorID>-<MapNumber>-TOPONYMS
- YYYY-MM-DD-<ContractorID>-DTM.dgn
- YYYY-MM-DD-<ContractorID>-DEM-GRID.dgn
- YYYY-MM-DD-<ContractorID>-REPORT.pdf,
where YYYY-MM-DD is date of deliverry, ContractorID represent name of company, MapNumber
represent map number and at the end content of files with file format. Examples of topographic data and
DTM data are shown on Figure 1 and Figure 2:
Figure 1: Example of topographic data
Figure 2: Example of DTM data
Sources which are used for control were Data inventory report, Data upgrade specification and
Mapping catalogue. For the control of toponyms there were aslo the old maps of TK25 used. Data
structure control included was done acoording to mapping catalogue which describes level, color, line
style and weight for linear objects, cell name for point elements and representation point (text) for areal
objects.
Control of topology included checking closing areas, duplicate lines and boundaries, open
boundaries, number of representation points in areas, missing representation points in areas, detecting
unused boundaries, etc.
Control of DTM included also checking of structure elements in files and deriving DEM from
delivered elements and detecting of possible errors.
2.3.2 QUALITY METHODS
There are two methods for quality control:
- Visual control with Microstation and SCOP
- Automatic control of data structure and topology (using FME).
Microstation was used for visual control of data. There was a system to control elements, which
were wrongly represented before data upgrade process. Mostly, bridges were wrongly represented,
roads were without center lines, waters were not represented under bridges (Figure 3) and culverts,
creating centerlines were also not enough precise (Figure 4).
Visual control of DTM was done with the help of derived shade (tiff format) and DEM (dgn format)
as shown on Figure 5. Some questionable parts on raster file are checked.
- 61 -
Figure 3: Water line not represented
under bridges
Figure 4: Unprecise creating
of road centerlines
Figure 5: Visual control of DTM
Automated quality control was done with FME (Feature Manipulation Engine) software. Partly
based on FME training and partly with help of CRONO GIP consultants in CGI the FME factory files were
used for checking the structure of datasets and for checking topology. The inputs for control of dataset
structure were all legal levels, colors, line styles and weights for linear elements, for point elements input
there was a list of symbol (crotis.cel file) and for area elements a list of codes (representation points).
FME detected all open boundaries, unused boundaries (which are not necessary for creating area
topology), missing classifications points (text codes), duplicate classifications points, overlapping lines
and boundaries, self intersected lines and boundaries.
2.3.3 RESULTS OF CONTROL
After the control, the results were divided to:
- Comments connected to undefined specification
- Comments connected to misinterpretation of specification
- Comments to topological processing.
In the process of quality control CGI detected some cases which are not enough described or
are not described in Specification. Typical example of that case is joining of road center lines. There was
no rule for joining narrow paths with road center lines which are very important for creating road network
topology (Figure 6).
Some producers interpreted object in their own way. Typical example is representing of culverts
(Figure 7)
Most comments connected to topology processing were in using wrong attributes for linear
elements (wrong color or weight for lines and boundaries). Distribution for errors and companies is
shown in Table 1.
- 62 -
Figure 6: Narrow path not connected to road centerline
Figure 7: Different ways of representing culverts
Table 1: Distribution error types for each company
Error type
Invalid element type
Invalid line attribute
Invalid boundary attribute
Unused boundaries
Missing classification point (textual code)
Unknown classification point
Excess classification points
Self intersecting lines
Self intersecting boundaries
Invalid cells
C1
C2
●
●
●
●
●
●
●
●
Company
C3
C4
●
●
●
●
●
●
●
C5
●
●
●
●
C6
●
●
●
●
●
●
●
●
●
●
●
2.3.4. REPORTS
For each company CGI wrote report, which includes:
- Introduction
- Authority for control
- List of Sources
- Content of control
- Findings
- General and single comments
- Comments connected to topologic processing
- Conclusion.
3. CONCLUSION
Croatian Geodetic Institute has done Data upgrade Quality Control of structure and topology
processing of topographic data in short period of time. Control of accuracy and correctness of
representation and classification have not been included in this process. Complete quality system should
be implemented at the end of the project.
- 63 -
Even though complete quality system was not implemented, CGI has done quality control in part
and results of control were very useful. Before completing the specification, some elements will be
changed and enhanced and the difference between producers reduced to accepted level. There is also a
team in CGI for all tasks and challenges. This test quality control confirmed that contention.
REFERENCES
Croatian Parliament, 1999, Law of state survey and real estate cadastre, Narodne novine br. 128/99,
Zagreb.
Statens Kartverk, 2001. Terms of reference for the implementation of component b) and c) of the
to build a National Spatial Data Infrastructure. Appendix A to the Contract, Oslo, Norway.
Program Management and Mapping, 2002. CRONO GIP Croatian Norwegian GeoInformation Project Inception study report, Zagreb, Croatia.
Program Management and Mapping, 2002. CRONO GIP Croatian Norwegian GeoInformation Project –
Data Inventory report, Zagreb, Croatia.
Program Management and Mapping (PMM), 2003. CRONO GIP Croatian Norwegian GeoInformation
Project – Data upgrade specification, Zagreb, Croatia.
International Organization for Standardization, 2001, ISO/DIS 19113 Geographic information – Quality
principles.
International Organization for Standardization, 2002, ISO/DIS 19114 Geographic information – Quality
evaluation procedures.
State Geodetic Administration, 2001, Book of Ordinances, Zagreb, Narodne novine br. 55/2001, Zagreb.
State Geodetic Administration, 2002, Croatian Topographic Information System CROTIS, Zagreb.
- 64 -
CREATING THE TOPONYMIC DATABASE OF THE REPUBLIC OF CROATIA –
PROJECT TOPONIMIS AS SUB-PROJECT OF STOKIS*
Stanislav Frangeš, Mladen Rapaić
ABSTRACT
Geographic names exist in our environment helping us to locate, define, describe and distinguish
various geographic objects. They are dependent and connected to the cultural and political influences
and are continuously changed and accommodated. The collection, notification and storage of geographic
names have been usual tasks in map preparation for the centuries. Nowadays, maps became one of the
main sources and on the other side, one of the main medias for publishing country toponyms. Although,
the responsibility in creation of the official maps and topographic databases belongs to the geodesists,
toponymy itself must be treated multidisciplinary. State Geodetic Administration and Croatian Geodetic
Institute of the Republic of Croatia are in stage of starting the second phase of TOPONIMIS project
which will prepare all necessary preconditions for creation of the national toponymc database.
KEYWORDS: Toponyms, Toponymic database, Topographic database, TOPONIMIS, STOKIS,
CROTIS, UNGEGN
1. INTRODUCTION
The United Nations Group of Experts on Geographic Names (UNGEGN) was founded according
to the resolutions of the Economic and Social Council (ECOSOC) for the purpose of solving the problems
referring to the names of states and cities in documents issued by various bodies of the United Nations.
The basic principle is contained in the intention to rely on standardisation of geographical names on their
national standardisations.
Many living and inanimate objects have their names that are mutually distinguished, so their
introduction into map make the cartographic presentation more informative. The names of general
geographic or topographic objects - toponymes are divided into:
- Conduct fundamental geodetic worksOronymes or the names of single relief features on the
Earth
- Hydronymes or the names of waters
- Regionymes or the names of fields, meadows, pastures, orchards, vineyards and forests and of
larger geographic units
- Econymes or the names of settlements
- Hodonymes or the names of traffic routes
- Territorionymes or the names of single areas under the authority of some state or other territorial
units (Lovrić 1988).
2. EXPERIENCES FROM ABROAD
In most of the countries, adequate institutions deal with content and lexical issues related to
geographic names working on their standardisation: Permanent Committee for Geographic Names
(Ständiger Ausschuss für Geographische Namen) in Germany, Working Group for Cartographic
Toponymy (Arbeitsgemeinschaft für topographische Ortsnamenkunde) in Austria, Committee for
Geographic Names in Denmark, Permanent Committee for the Standardisation of Geographic Names
within the frame of Royal Geographic Society in Great Britain, Commission for the Standardisation of
Geographic Names in Slovenia and others. It is not just important but essential that those institutions
have been established by the legal action (law, order, directive) by their state Government and have
legal authority to run the project. UNGEGN published the manual which gave essential recommendations
for establishing such bodies. According to that manual (Orth, 1990), the establishment of country names
*
zborniku radova (Frangeš, S., Rapaić, M.: Creating the toponymic database of the Republic of Croatia –
Project Toponimis as sub-project of Stokis. Proceedings of the International Society for Photogrammetry
and Remote Sensing (ISPRS) WG VI/3 Workshop: "GeoInformation for Practice", 15-18 October 2003,
ISSN 1682-1750, Zagreb, Croatia).
- 65 -
authority have, among others, two main reasons: it guarantees continuing status of the work and it
clearly states commission, powers, privileges and areas of responsibility.
At the meetings of the United Nations Group of Experts on Geographic Names it has been urged
from the member states to publish standardised geographic lists (Croatia has got only the List of
Settlements of the Republic of Croatia so far published by the State Institute for Statistics) that would
make the work easier for cartographers and other publishers. This Group recommends that the lists
should contain the data about the type of an objects that the name refers to, exact positional description
and expansion area, map sheet name where it is placed etc. Since the publication of such lists is very
expensive and the data are not updated, it is recommended for toponymic database to be produced in
digital form.
Dissemination of toponymic database is final and crucial step and it justifies all efforts and
money invested into the work of geographic name authorities. The evolution of Internet gave opportunity
to publish the database and all related documents in easiest possible way and to the world-wide
audience. Good and encouraging examples are the Gazetteers of Canada (Natural Resources Canada),
Estonia (Institute of the Estonian Language), United States (United States Geological Survey) and United
Kingdom (PCGN).
3. SITUATION IN THE REPUBLIC OF CROATIA
So far, the Republic of Croatia has got no authority constituted at the official, state level that
would deal with Croatian and international geographic names in systematic and organised way. The
competencies for changing the names of administrative units are regulated by the laws. Thus, the House
of Representatives in the Croatian National Parliament makes the decisions referring to the areas of
counties, cities and municipalities (name, area and the residence of the county, city and municipality),
and the county assemblies are responsible for giving names and making decisions about names and
borders of settlements areas. Borders and names are kept in the Register of Spatial Units in the State
Geodetic Administration.
The users of geographical names have great problems already in using the names of
settlements in the Republic of Croatia because of frequent changes in recent years and because of
printing and other mistakes in official documents. The problems (inconsistency, incorrectness,
uncertainty) also appear in using the names of other states and in using our traditional names of foreign
geographic features (e. g. Kopenhagen – København).
Geographic names have great significance for each country and nation since they reflect
landscape, express national identity and are cultural heritage. They are used in all aspects of society,
from production of geodetic plans and topographic maps, publication activity, education and urban
planning, to environmental protection, tourism, economy, foreign affairs etc., therefore, it is necessary to
pay larger attention and to organize the collaboration of various professions.
Since the problem of correct usage of foreign and homeland geographic names is present in
state official documents, cadastral plans, topographic and other maps, encyclopedias, school and other
atlases, on the radio, television, internet and in the newspapers it is necessary to work on the
standardisation of national and international geographic names, on the production of toponymic guides,
national geographic register, abbreviated geographic register etc. (Buljat 1997).
According to Official Topographic and Cartographic Information System - STOKIS (State
Geodetic Administration 1995) an object can have more names that are distinguished by the type. Three
types of names are foreseen:
- Geographic names, generally used object name
- Second name, folk or tourist description existing along with the geographic name
- Classification name, abbreviations, numerical signs etc.
According to Topographic Information System of the Republic of Croatia - CROTIS (State
Geodetic Administration 2000) the toponymes present an object entity classified into the following groups
and then subgroups:
- Regionymes
o area (region), field, lawn
- Oronymes
o mountain, mountain-range, foothills
o pass, valley, cliff, gorge, crest, slope
o pick, saddle, rock
- Hydronyms
o bay, cove, cape
o sea region
- Names of islands
- 66 -
o
o
Islands
rock, crest, sea shallow.
3.1. PROJECT TOPONIMIS, THE FIRST PHASE
The entire project TOPONIMIS, as sub-project of STOKIS is therefore intended for creating an
adequate toponymic digital database that would contain geographic names adjusted to:
- Accelerated production of all maps and maps of related presentations, with an accent on official
cartographic publications
- Consequent and correct usage of geographic names for official cartographic publications
- Various GIS users of spatial data
- Official usage.
The first phase is planned for:
- Creation of an adequate information subsystem that would encompass all geographic names
according to the defined logical structure that in any way appears in official usage of state maps,
- Categorisation of toponyms in accordance with the STOKIS and CROTIS,
- The establishment of contacts between adequate institutions (State Geodetic Administration,
Croatian Geodetic Institute, Croatian Academy of Sciences and Arts, Croatian School
Cartography, Croatian State Archives, Croatian Hydrographic Institute, Lexicographic Institute
"Miroslav Krleža" etc.) and professionals.
Within the scope of the project TOPONIMIS, the research has been carried out that led to the
working version of an establishment concept for the information system that would encompass all
geographic names according to the defined logical structure that in some way appear in official usage on
state maps. It includes the following names:
- Settlements (towns, part of towns – districts, villages) supplemented by the names of hamlets
and categorised according to defined criteria,
- Geographic entities (areas, lawns, islands, peninsulas, capes etc.)
- Those connected with hydrography (sea, bays, inlets, harbours, ports, shallow waters, lakes,
rivers, streams, canals, swamps etc.)
- Those connected with relief (massif, mountains, mountain-ranges, foothills, passes, valleys,
cliffs, crests, peaks, rocks, caves, steep rocks, etc.)
- Those connected with political, administrative and statistical classification (names of neighboring
countries, counties, cities, municipalities, settlements, cadastral municipalities, etc.) (State
Geodetic Administration 2002).
3.2. CONTINUATION OF THE PROJECT
In the second phase of the project it is planned to do the following:
- The active involvement of adequate institutions and professionals who are directly of indirectly
connected to the project
- Establishment of official contact with United Nations Group of Expert on Geographical Names
- Gathering relevant information and experiences from other countries
- Gathering relevant information from various users of future toponymic database
- Creation of database concept and technological environment for realisation of next phase.
The third phase would be the phase of implementation, with following tasks:
- Entering the data gathered in the process of producing new digital Croatian Base Map (HOK)
and the Topographic database into toponymic database
- Entering the data gathered in the preparation for printing HOK into toponymic database
- Controlling by adequate state institutions
- Defining the procedures for maintaining the toponymic database.
Along with realization of TOPONIMIS project, the parallel process of establishment the
governmental body responsible for the standardization of geographical names have to be conducted. All
participants in project, led by the State Geodetic Administration, should put effort in arising the
awareness in the whole community for necessity of that decision. It can be even stated that all invested
time and money will be in vain if no standardization body will not exist to approve, maintain and overtake
the responsibility.
4. TOPONYMIC DATABASE
In this early stage of preparing the start of future project, general idea of toponymic database
exist in form of ideas, professional discussions, wishes and knowledge of realised databases in other
- 67 -
countries. One fact is certain and that's the name of the institution that will run the database. Croatian
Law of State Survey and Real Estate Cadastre strictly defines in the Article 44 that Croatian Geodetic
Institute "establishes and kept the register of geographical names" (State Geodetic Administration, 1999)
which give to the Institute not just right, but obligation to conduct and run preparation of this task.
Source
The ongoing project CRONO GIP (Croatian Norwegian GeoInformation Project) has several
components (sub-projects) and one of them is establishment of the Topographic database in the State
Geodetic Administration (SGA) of Croatia related to production of Topographic map 1:25000. According
to project documentation (State Geodetic Administration, 2001), geographic names exist in that
database in two forms: firstly, as stand-alone objects in separate Feature category, not related or
connected to any specific topographic object and secondly, as attributes of existing topographic objects.
The main sources for collecting and storing toponyms in the SGA's Topographic database are existing
and official Topographic map 1:25000 (TK25), existing official gazetteers (e.g. for settlement names) and
field checking. This database will be the starting point and the main source for toponymic database. The
reasons are more than obvious: professionally correct and accurate data, data stored in organized,
modern and documented way and very strong economic reason: using existing data with investment only
in additional and necessary procedures (standardisation, attribution, linkage with other databases and
other that will be defined in the future).
During developing phase of CRONO GIP project, some of the existing digital data already
created in previous production of TK25 have been examined and for testing purposes prepared for
uploading into the Topographic database. Following figures presents in graphical way position of names
of the settlements (Figure 1), names of the geographic entities (Figure 2), the hydrographic names
(Figure 3) and the relief names (Figure 4) on the same area.
Figure 1: Settlement names
Figure 2: Geographic area names
Figure 3: Hydrographic names
Figure 4: Relief names
Figure 5 presents dispersion of all toponyms along the same area, the area that is covered by
one map sheet – Pićan, in scale 1:25000.
- 68 -
Figure 5: All toponyms
Number of toponyms divided into four categories (A - names of the settlements, B - names of the
geographic entities, C - hydrographic names, D - relief names) on six various map sheets are presented
in Table 1.
Map name
A
B
C
D
Nin
38
38
28
24
Murvica
75
62
6
65
Škabrnja
64
100
48
41
Pićan
229
34
18
60
Kupljenovo
70
60
38
20
Rasinja
0
58
17
33
Table 1. number of toponyms on various maps TK25
Database concept
Technical details among which is the database design, are not yet defined and are directly
connected to desired level of usability and possibility for multiple users of multiple disciplines to use it.
One of the main questions that will have to be answered will be repetitivity of the same toponym: will
there be just one to one relations between object and it's name or one-to-many relations, where for one
object more repetitions (because of positioning on various map sheets) of the same toponym will be
allowed. Investigation of other country's experiences and exact examples is still in process by the staff of
the Croatian Geodetic Institute. The establishment of contact with the United Nations Group of Expert on
Geographical Names (UNGEGN) and it's Working Group on Toponymic Data Files and Gazetteers is
essential part in this preparation process. Number of attributes that describes toponyms vary from
country to country.
At this point, it can be said that mandatory attributes that should be connected to each record in
the Croatian toponymic database will be:
- Type/category/class of topographic object to which toponym belongs, according to the
Topographic database documentation
- Identification number of topographic object for connection with the SGA's Topographic database
- Identification number of the toponym
- Source from which toponym is put into the Topographic database
- Vintage of the source
- Coordinates of the principal point of the toponym. Toponymic project will have to determine
definition of the principal point for each topographic feature
- Descriptive position, which can be either name and/or nomenclature of map sheet of certain
scale, municipality name or other local administrative unit's name.
The quality of toponymic database will arise if more attributes could be added. Some of the
attributes that can be put in database are:
- Variant name, which can be the same toponym written in other form or in other language
- Cartographic name, variant of toponym used on a map (for example abbreviated name)
- Status of standardisation of toponym, (for example officially approved, historic, etc.)
- 69 -
Coordinates that define position of the topographic object, (for example, minimum and maximum
coordinate values)
- Numerical value (for example number of inhabitants or mountain height)
- Link to the superior topographic object of the same topographic feature category (for example,
mountain peak linked to mountain, mountain linked to mountain chain)
- Identification number of toponym or topographic object from gazetteer that was source for
toponym.
Number of additional attributes can be even larger, but optimum level will be defined after
thorough optimisation of expected expenses related to expected data quality.
-
5. CONCLUSION
The production of a comprehensive register of geographic names is an extensive, but necessary
and still not initiated work that the Croatian official geodesy is to be faced with. With regard to the
importance, extensiveness and significance of producing an adequate toponymic database it is
indispensable to establish the collaboration on a wide level that would include geodesists, geographers,
cartographers, linguists, historians and others.
Although creation of toponymic database is important and is tremendous effort, without
establishment of official governmental body that will be responsible for the content and maintaining of
database, results of those efforts will not be fully accepted among users and by time can be overridden
by other unformal, unofficial and unreliable gazetteers.
Along with establishment of principles and procedures for using and creating toponyms on
official, Croatian language, the care has to be taken also to the minority languages, narrative names and
to non-Croatian toponyms, the way that toponyms are used in languages of neighboring languages.
REFERENCES
Buljat, J., 1997. Međunarodne aktivnosti normizacije geografskog nazivlja, Geodetski list, 2, pp. 158161.
Orth, D.J., 1990. “Organization and functions of a National Geographical Names Standardization
Programme: A Manual.”, World Cartography, Vol. XXI, New York, United Nations, pp. 11-40.
Lovrić, P., 1988. Opća kartografija, Liber, Zagreb.
State Geodetic Administration, 1995. Službeni topografsko-kartografski informacijski sustav – Idejni
projekt, Zavod za fotogrametriju d.d., Zagreb.
State Geodetic Administration, 1999. Law of state survey and real estate cadastre, Narodne novine br.
128/99, Zagreb
State Geodetic Administration, 2000. Topografsko informacijski sustav Republike Hrvatske – CROTIS,
Temeljna načela – Katalog objekata, verzija 1.0, GEOFOTO d.o.o., Zagreb.
State Geodetic Administration, 2001. Object Catalogue, version 1.1, Croatian Topographic Information
System - CROTIS, Zagreb, Croatia
State Geodetic Administration, 2002. Projekt Toponimika – nazivlje, I. faza, Sveučilište u Zagrebu –
Geodetski fakultet – Zavod za kartografiju, Zagreb.
Natural Resources Canada, Canadian Geographical Names, http://geonames.nrcan.gc.ca/index_e.php,
(accessed 20 May 2003),
Institute of the Estonian Language, http://www.eki.ee/knab/knab.htm, (accessed 20 May 2003),
United States Geological Survey, Geographic Names Information System, http://geonames.usgs.gov/,
(accessed 20 May 2003),
PCGN: The Permanent Committee on Geographical Names for British Official Use, http://www.pcgn.org.
uk/Indexx.htm, (accessed 20 May 2003)
- 70 -
SPECIFIČNOSTI GEODETSKE OSNOVE U TUNELOGRADNJI*
Ilija Grgić
SAŽETAK
U ovome istraživanju željelo se pokazati da li primjena GPS-a u tunelogradnji može u potpunosti
zamijeniti do sada primjenjivane načine razvijanja mreža, bez nužnosti izvođenja terestričkih mjerenja, a
da se pri tom jamči proboj tunela u okviru dozvoljenih odstupanja. Dalje se željela izvršiti usporedba
točnosti proboja tunela ukoliko su koordinate mikromreža određene GPS tehnologijom u odnosu na
mikromreže koje su određene terestričkim mjerenjima. Radnja obuhvaća razvijanje mikromreža u
tunelogradnji na nepristupačnim terenima kada je nemoguće, ili teško moguće ostvariti vezu mikromreža
terestričkim mjerenjima razvijanjem lanaca trokuta ili četverokuta (miniranost terena), načine opažanja,
izvore pogrešaka, te analizu i interpretaciju konkretnih rezultata dobivenih tijekom rada na projektu tunela
“Sveti Rok”. Nadzemnu geodetsku osnovu čine dvije samostalne mreže koje povezuje precizni poligonski
vlak preko Velebita. Podzemnu geodetsku osnovu čine dva slobodno vođena poligonska vlaka duž jedne
i druge strane tunela, s time da je izvršena stabilizacija samo za jedan slobodni poligonski vlak duž jedne
strane. Obavljene su različite vrste izjednačenja: GPS mjerenja, triangulacije i trilateracije za obadvije
mreže, kao i kombinirano izjednačenje s preciznim poligonskim vlakom. U svim izjednačenjima
terestričkih mjerenja korišten je Gauss-Markovljev model posrednih mjerenja uz načelo najmanjih
kvadrata.
ZUSAMMENFASSUNG
Das Ziel dieser Forschung war zu zeigen ob die bis jetzt angewendeten Methoden der
Netzentwicklungen im Tunnelbau durch die Anwendung des Globalen Positionierungssystems GPS
erfolgreich ersetzt werden kann, ohne terrestrische Messungen durchführen zu muβen, daβ dabei der
Durchschlag des Tunnels gewährleistet wird. Das weitere Ziel war die Durchschlagsgenauigkeiten des
Tunnels zu vergleichen abhängig davon ob die Koordinaten des Netzes mittels GPS Messmethoden
bestimmt worden sind im Bezug zu den Koordinaten des Netzes die mittels terrestrischen Messungen
bestimmt worden sind. Diese Magisterarbeit erfaβt die Netzentwicklungen in dem Tunnelbau auf den
unzugänglichen Gebieten, wenn es unmöglich oder bedingt möglich ist die Verbindung der Auβennetze
durch die Entwicklung der Dreiecks- bzw. Vierecksketten zu verwirklichen (durch die Mienen verseuchtes
Gebiet), die Beobactungsmethoden, die Fehlerquellen und die Analise und die Interpretation der
konkreten Ergebnisse, die durch die Bearbeitung der durchgeführten Messungen aus dem Projekt des
Tunnels «Sveti Rok» hervorgekommen sind. Das überirdische Vermessungsnetz bilden zwei freien
Netze, die ein präziser Polygonzug über Velebit verbindet. Das unterirdische Vermessungsnetz bilden
zwei freigeführten Polygonzüge entlang der beiden Tunnelseiten, wobei die Vermarkung nur für ein
freigeführter Poligonzug gemacht worden ist. Es sind unterschiedliche Arten der Ausgleichung
durchgeführt worden: die Ausgleichung der GPS Messsungen, die Ausgleichung der Richtungs- und der
Streckenmessungen der beiden Netzen, sowohl die Ausgleichung des kombiniertes Netzes mit dem
präzisen Polygonzug über Velebit. In allen Ausgleichungen der terrestrische Messungen ist der GauβMarkoff-Modell der vermittelten Messungen mit der Methode der kleinsten Quadrate angewendet
worden.
*
Magistarski rad obranjen na Geodetskom fakultetu Sveučilišta u Zagrebu 14.11.2003. godine.
- 71 -
- 72 -
CHANGES OF BENCH MARK HEIGHTS BEING THE CONSEQUENCE OF
INTRODUCING THE NEW CROATIAN HEIGHT SYSTEM*
Nevio Rožić
ABSTRACT
In the period between 1994-2002 there were rather extensive works carried out in the Republic
of Croatia on the improvement of national levelling networks and the height system based on the existing
(archive) data of geometric levelling measurements. The results of these works are the basis for
introducing the improved (new) Croatian height system into official usage. The differences in definition
and realisation between the improved (new) and existing (old) Croatian height system are, among other
things, directly reflected on the changes of national levelling bench mark heights. On the basis of the
bench mark heights comparison it is possible to define and analyse the level of mutual disparity and
distortion of height systems. For this purpose, the bench mark heights in the national geometric levelling
networks have been analysed, as very indicative, in the northern part of the territory of the Republic of
Croatia.
1. INTRODUCTION
The systematic works on the improvement of the existing height system, that was initially defined
and realised in the period 1875-1914 as Croatia was the integral part of the Austro-Hungarian Monarchy
and that was additionally updated and modernised with numerous new works on geometric levelling of
various orders in the period 1945-1970 as Croatia being the part of former Yugoslavia, started during the
year 1994 and were completed by the end of 2002. The stated systematic works were based on the
repeated computing processing of the existing (archive) data referring to the levelling network
measurements, considering the objective and material circumstances that the Republic of Croatia found
itself in at the beginning of the nineties after gaining its independence, with introduction of the "new"
fundamental height network, as well as the new height datum. The network of the so-called II. levelling of
the high accuracy (IINVT) that had been made at the territory of the western part of former Yugoslavia in
the period 1970-1973, leaning on five tide gauges along the Adriatic coast (Koper, Rovinj, Bakar, Split
and Dubrovnik), was introduced as the "new" fundamental height network at state territory. Due to some
objective circumstances, i.e. very long period of analysis and data processing, network was not used
until 1992. The detailed data about the previously mentioned works on the improvement of the height
system in Croatia can be found in the reports and articles presented at EUREF symposia in previous
years Feil et al. 1992, Feil et al. 1993, Klak et al. 1996, Rožić et al. 2000, Rožić 2003, and the
informations about various aspects and problems connected with the national levelling networks and the
height system at the territory of Croatia can additionally be found in Feil et al. 1999, Feil et al. 1999a,
Rožić 1999, Rožić 2001.
Considering the fact that there is the process of putting of the new height system into the official
usage going on at the moment, the issue of investigation the congruence level, i.e. the differences
between the bench mark heights included into national geometric levelling networks is being raised as a
very interesting issue. The differences between the height systems and their influence on bench marks
heights, in the geometric levelling networks at the northern part of the Republic of Croatia, are very
indicative and usable for that purpose.
2. OLD HEIGHT SYSTEM
The old height system (at the moment still the official height system) of the Republic of Croatia
was established during the time of the Austro-Hungarian Monarchy as a normal orthometric height
system, and it was realized through the network of the so called Austrian Precise Levelling (APN). The
origin bench mark in the system was the bench mark HM 1 placed in the vicinity of the tide gauge at
Molo Sartorio in Trieste. It absolute height is defined in relation to the mean value of the Adriatic Sea
water level obtained from the one-year measurements in 1875, and it is 3.3520 m. After the Second
World War, referring to about forty years that passed after the establishment and the realisation of APN
održanom u Bratislavi, Slovačka, 2.-5.6.2004. godine. Objavljeno u Zborniku radova Simpozija (u tisku).
*
- 73 -
network, and considering a great number of destroyed bench marks, the network was reconstructed
through an extensive new bench mark stabilisation and through the repeated levelling of levelling lines
within the frame of performing the so called I. levelling of high accuracy (INVT) of former Yugoslavia. In
the realisation of the INVT network some discrepancies occurred relating to the geometric configuration
of the APN network, first of all for the purpose of eliminating a few longer levelling lines in Dalmatia and
defining geometrically closed and firm figures. The measurements of INVT were made gradually and in a
longer period of time, from 1945 till 1963, and the determination of bench mark heights (measurement
adjustments) were made successively and in accordance with the survey dynamics, whereby the new
measurements were adjusted on the old (preserved) APN network bench marks, Fig. 1.
47°
47°
AUSTRIJA
ITALIJA
321
14
5
122a
122
Rovinj
20242
Pula
122
MVIII
MLVIII
IV
III
HM504
I 13
II
23
41/13 271
CMXVI
5696
Čakovec 271
VI
272
266
273
274
306
IX
4/307
Otočac
DCCLIII
VII
2900 2797
MLII
Oštarije
1727
Virovitica
265
263
X
264
3339
Kostajnica
304
3165
Drežnik
280
BV11378
3387
3317
307
XIV
302
1/318
Sv.Rok
318
BV15881
XVIII
MCCCXXII
Knin
317
XVII
MCCCXCV
3467
283
XII
278
BV12720
BV12554
284
MCLXVIII
0
285
XX
291
315
508
XIX
110/286
I. NIVELMAN VISOKE TOČNOSTI
XVI
449
286
REPUBLIKA HRVATSKA
281
282
BV13338
MCCCXCI
Sinj
276
277
XV
485
292
MCCC
Split
261
2045
262 Sl.Brod
BV11377
Vinkovci
279
301
300
248
BV10745
Borovo
252
VIII
BiH
MCDLXXXIV
XIII
298
BV13025
DCCXXVIII BV10650
Osijek
Dalj
198
XI
280
304
305
MAĐARSKA
266
MDL 259
BV11631
Zagreb
V
275
320 2203
Rijeka
322
3597
SLOVENIJA
7
MCCCLVIII
MDX
HM404 11
68/284
317
XXI
316
DCLXXVIII
95/318
289
XXII
318
84/317
10
20
30
40
50 km
Tumač znakova:
čvorni reper
mareograf
nivelmanski vlak
br. nivel. vlaka
295
293
4/297
Dubrovnik
DCLXVI
DCXXXXVII
296
Geodetski Fakultet
42°
42°
13°
23°
Fig. 1. INVT levelling network at the territory of the Republic of Croatia
Along with the realization of the INVT network, there were also many levelling works on lower
order geometric levelling networks made (precise levelling - PN, city levellings - GN, technical levelling of
increased accuracy - TNPT, technical levelling - TN) that cover relatively regularly the whole state
territory. The adjustments of measurements in the lower order geometric levelling networks was made in
a hierarchical order by lower order levellings leaning on higher order levelling networks, by applying the
condition measurements adjustment using the method of least squares. It should be pointed out that in
terms of accuracy the measurements were partly inhomogeneous, and in terms of hierarchic data
processing the adjustments of more complex networks were avoided by simplifying their geometric
configurations. The quantity of the performed works is expressed by the number of 423 levelling lines at
the entire territory of the Republic of Croatia, i.e. in accordance with the classification into the accuracy
orders: 36 INVT levelling lines, 77 precise levelling lines, 49 city levelling lines (networks), 149 increased
accuracy technical levelling lines and 112 technical levelling lines.
3. NEW HEIGHT SYSTEM
In the period 1970-1973, a new high accuracy levelling network was made at the western part of
former Yugoslavia, i.e. the network of so called II levelling of high accuracy (IINVT) that should have
been used as the basis for the establishment of the new height system. The new height system should
have removed the weakness of the existing system, which means that it should have been updated, it
should have had adequate accuracy and removed the error in determining the origin bench mark height
(bench mark HM1) in the old height system. The geometric configuration of the IINVT network is
therefore designed and performed mostly in disparity with the existing INVT network, and the IINVT
network is at the same time connected with five tide gauges at the Adriatic coast (Koper, Rovinj, Bakar,
- 74 -
Split and Dubrovnik), Fig. 2. The absolute heights of the 5 new origin bench marks in the IINVT network
were determined at all tide gauges in relation to mean water levels of the Adriatic Sea for the time epoch
of 1971.5, from the measurement interval of 18.6 years.
47°
47°
AUSTRIJA
HM404
C907
C16
ITALIJA
PN305
FR3052
II
2753
7
8
SLOVENIJA
BP82
Rovinj
I
2
12
III
FR1029
Brajkovići
BV
MCXVII
Bakar
11
10
C46
Senj
21
9
IV
A437
Novska
CP695
Kostajnica
22
MCCI
Ž.Lokva
51
16
FR3020
Zagreb
64
5
1
FR3116
15
MCDLV
A56
14
FR3053
Varaždin
6
5486
Koper
MAĐARSKA
13
65
17 C143
Pčelić
DCCLIII
Virovitica
41
18
BV11530
19 Daruvar
VIII
37 C650
Okučani
O362
Batina 45
46
CP317
Osijek
48
K274 43
Našice
38
36
VII
39
XI
V
XII
FR1065
49
40
OP477
VI
FR1069
32
REPUBLIKA HRVATSKA
C694
XIII
28
25
47
50
27
FR3119
54
FR3102
BiH
53
C880
FR3063
O472
26
IX
X
Strizivojna
FR1039
24
FR3118
44
42
20
23
52
FR3114
55
FR1067
33
29
A473
FR1085
0
C162
Šibenik
31
3
XIV
BV14530
MCCC
Split
PN167
30
56
34
20
30
40
50 km
Tumač znakova:
A377
35
10
57
reper
XV
58
čvorni reper
61
C346
Opuzen
mareograf
FR1089
XVI
nivelmanski vlak
br. nivel. vlaka
63
FR1098
4
C620
Dubrovnik
A496
59
Geodetski Fakultet
62
60
FR1094
42°
13°
42°
23°
Fig. 2. IINVT levelling network at the territory of the Republic of Croatia
Referring to the fact that along the levelling lines in the IINVT network the gravimetric
measurements have not been carried out completely and systematically, and that the measuring data
processing and analysis was carried out during a very long period, i.e. between 1973 and 1992, it full
implementation was not enabled till beginning of the nineties within the frame of the realisation of the
new normal-orthometric height system to be practically used at the territory of the Republic of Croatia. In
the period between 1994 and 2002, all existing low order geometric levelling networks were connected to
this network, and in parallel with field revision of bench marks included into these networks, there was a
complete and systematic computation and systematic processing of original measuring data made, i.e.
the new network adjustments (readjustments). The measurements were adjusted consistently by indirect
measurements adjustments using the least squares method and keeping the hierarchical order of
processing, i.e. leaning the lower order geometric levelling networks to higher order networks, and in
accordance with the pre-systematized geometric configurations of the networks without their
simplification in spite of the complexity. With reference to the works done, a new and updated applicable
documentation was made for all preserved bench marks of levelling networks, including the sketches of
levelling networks and figures, positional descriptions, positional bench mark coordinates in the state
coordinate systems, heights etc.
4. RELATIONSHIP OF BENCH MARK HEIGHTS IN THE NORTHERN PART OF CROATIA
Referring to the fact that the old and the new height system of the Republic of Croatia are
normal-orthometric systems realized at the same territory, to a great extent on the basis of the same
measurement data, i.e. the same geometric levelling networks, they can be compared between each
other. The most interesting is the comparison of the heights of all bench marks that are present in both
systems at the same time, because it indicates congruity level of both systems, the size and regularity of
difference distribution in heights and its influence on performing the practical works that require the
knowledge of the heights. Considering the way of defining and establishing the height systems, it is clear
that the differences in bench mark heights result from the mutual influence of a few various reasons:
- the difference in number, procedure and time epoch of determining the origin bench marks
heights (height datum) in the fundamental height networks, and in their position as related to the
- 75 -
geometry of these networks. In the case of INVT it is HM1 in Trieste (the epoch of the year 1875
- the mean of one-year see level measurements), Fig. 1, and in the case of IINVT these are the
bench marks 5486 - Kopar, BP82 - Rovinj, BV - Bakar, PN167 - Split and A496 – Dubrovnik
located at the five tide gauges (the epoch of the year 1971,5 - the see level mean from the
interval of 18,6 years), Fig. 2.
the difference of geometric configurations in the fundamental height networks, i.e. INVT and
IINVT, as well as difference of the used adjustment methods for these networks, Fig. 3. In the
case of INVT the individual levelling lines and the parts of the network have been adjusted
separately referring to the fixed base (preserved bench marks) of the network APN, and the
network IINVT has been adjusted as the homogeneous network using indirect measurements
and the method of least squares.
-
47°
47°
ITALIJA
AUSTRIJA
MAĐARSKA
SLOVENIJA
BiH
REPUBLIKA HRVATSKA
II NVT i I NVT
0
10
20
30
40
50 km
Tumač znakova:
II NVT
I NVT
Geodetski Fakultet
42°
42°
13°
23°
Fig. 3. Relation of the networks INVT and IINVT at the territory of Croatia
-
-
the difference of geometric configurations and adjustment procedures (methods) in adjusting the
networks of lower order geometric levellings being the consequence of their re-systematization
conditioned by the change of geometric configurations in fundamental networks that they are
connected to, i.e. INVT and IINVT.
influence of height instability of bench marks contained in the measuring data, referring to the
fact that works on geometric levellings have been carried out in essentially different time epochs,
i.e. the network APN in the period 1875-1914, the network INVT in the period 1945-1963, the
network IINVT in the period 1970-1973 and the networks of lower order geometric levellings in
the period 1945-1970.
The size, distribution and changes of the bench mark heights between the old and the new
height system should be considered in the northern part of the Republic of Croatia determined by the II.
and III. levelling figure of the IINVT network, Fig. 2. The mentioned area bordered by the state border of
the Republic of Croatia with the Republic Hungary and the Republic Slovenia, as well as with the IINVT
levelling lines: No. 8 (Dobova – Zagreb), No. 21 (Zagreb – Kostajnica), No. 20 (Kostajnica – Novska),
No. 19 (Novska – Daruvar), No. 18 (Daruvar – Pčelić), No. 17 (Pčelić – Virovitica) and No. 74 (Virovitica
– Terezino polje), contains altogether 2105 bench marks, Fig. 4., with: 182 IINVT bench marks (red), 108
INVT bench marks (violet), 274 PN bench marks (brown), 863 GN bench marks (blue), 416 TNPT bench
marks (green) and 262 TN bench marks (black). The concentration of bench marks and their horizontal
distribution referring to the entire territory of the Republic of Croatia is presented on Fig. 5.
- 76 -
5150000
5140000
5100000
5050000
5120000
5000000
5100000
4950000
5080000
4900000
5060000
4850000
5040000
4800000
4750000
5020000
4700000
2440000
2460000
2480000
2500000
2520000
2540000
2560000
2580000
Fig. 4. Bench marks
2300000 2350000 2400000 2450000 2500000 2550000 2600000 2650000 2700000
Fig. 5. Bench marks at territory of Croatia
The differences of bench mark heights dH at the observed territory Rožić 2003a obtained by
subtracting the bench mark height in the new height system from the belonging value in the old height
system have got the value between minimum 122.6 mm and maximum 250.2 mm, and they are all
contained in the interval sized 127.6 mm. The statistic indicators describing their properties, as well as
the properties of bench mark coordinates in the horizontal projection plane (Yn, Xn) are shown in the
table 1.
Table 1. Statistical indicators
Size
Yn
Xn
dH
Minimum
2431761 m
5004864 m
122.6 mm
Medium
2489510 m
5076343 m
171.1 mm
Maximum
2580206 m
5153316 m
250.2 mm
Interval
148445 m
148452 m
127.6 mm
Average
2493728 m
5082973 m
174.6 mm
Variance
1227780389 m2
956324519 m2
537.9 mm2
Stand. error
35040 m
30924 m
23.2 mm
The behaviour of the differences of heights at the arbitrarily selected discrete points at the entire
observed territory defined on the basis of the dependence on their values at bench mark positions is
graphically presented by the continuous spatial surface modelled by applying the method of "krigging"
and the additional filtering. The spatial surface shape, the mutual relation between the surface and the
bench mark positions are presented on Fig. 6. It should be pointed out that the shape of the surface
outside the area borders is rather instable because it has been determined by means of data
extrapolation.
Fig. 6. Relation between the spatial surface and bench marks
- 77 -
Fig. 7 presents the same surface, but orthogonally projected into the projection plane and
supplemented with contour lines.
Fig. 7. Contour lines of height difference of bench marks
5. CONCLUSION
On the basis of the numerical data from the table 1 and graphic presentations on Fig. 6 and 7 it
is possible to make principal conclusions that describe the empirical rules of behaviour in the height
difference of bench marks encompassed at the same time by the old and new height system of the
Republic of Croatia.
All height differences are positive, i.e. the bench mark heights in the old height system are bigger
than the heights of the same bench marks in the new height system. This fact is in accordance with the
results of investigation the relation of height datums in the old and new height system, i.e. with the error
in determining the height of the origin bench mark (the bench mark HM1) in the network APN in the old
height system for which the value has been defined to be about 12 cm Feil et al. 1992, Feil et al. 1993.
It is very interesting that the minimum height difference of bench marks of 122,6 mm at the observed
territory is also logically in congruence with previously cited value and shows that all official heights at the
territory of the Republic of Croatia are initialy bigger than heights corresponding to correctly determined
mean sea levels of the Adriatic sea at the locations of five tide gauges. At the same time mean see levels
at all five tide gaugages are mutually in a very good accordance. The size of the interval where the
height differences of bench marks are to be found is rather big and amounts at the observed territory up
to 127,6 mm which indicates to the fact that significantly different fundamental networks, the changes of
geometric configuration of the lower order networks have essentially affected the changes of heights
along with various adjustment methods and procedures. The consequence of this influence is not only
the difference of bench mark heights, but also their positional distribution and the pattern of changes
depending on the position of bench marks in the plane coordinate system. The differences of bench mark
heights show some trend regularities of changing depending on the bench mark positions in the plane,
Fig. 7. This trend regularity is expressed especially in the direction north-south and much less expressed
but still noticeable in the direction west-east. Certain areas of the observed territory indicate relatively
high distortions. Generally speaking, the differences of bench mark heights are changing irregularly
- 78 -
along the observed area and rather significantly referring to their size.
Considering the irregularities of changes and the size of differences in bench mark heights one
can expect rather difficult determination of a model for the transformation of height data between the old
and the new height system of the Republic of Croatia.
REFERENCES
Feil, L., Klak, S., Roić, M., Rožić, N. (1992): Beitrag zur Bestimmung der Vertikalkrustenbewegungen in
Kroatien. Österreichische Zeitschrift für Vermessungswesen und Photogrammetrie, 1992, Heft 2,
95-106.
Feil, L., Klak, S., Rožić, N. (1993): Nivellement von hoher genauigkeit auf dem gebiet der Republik
Kroatien. Österreichische Zeitschrift für Vermessungswesen und Photogrammetrie, 1993, Heft 4,
176-182.
Feil, L., Klak, S., Rožić, N., Gojčeta, B. (1999): National report of the Republic of Croatia on the high
system. Mitteilungen des Bundesamtes für Kartographie und Geodäsie, Band 6, EUREF
Publication No. 7/I, Frankfurt am Main, 1999, 142-148.
Feil, L., Klak, S., Rožić, N., Gojčeta, B. (1999a): National report of the Republic of Croatia on the height
system. Veröffentlichungen der Bayerischen Kommission für die Internationale Erdmessung der
Bayerischen Akademie der Wissenschaften, Report on the Symposium of the IAG
Subcommission for Europe (EUREF) held in Prague, 2-5 June 1999, München, 1999, Heft Nr.
60, 146-149.
Klak, S., Feil, L., Rožić, N. (1996): Connection of height systems of Hungary and Croatia. Acta
Geodaetica et Geophysica Hungarica, Budapest, 1996, Vol. 31 (1-2), 25-35.
Rožić, N. (1999): Erhaltung der Reperepunkte im Österreichischen Präzisionsnivellement auf dem
Gebiet der Republik Kroatien. Österreichische Zeitschrift für Vermessung & Geoinformation,
1999, Heft 4, 188-195.
Croatia. Acta Geodaetica et Geophysica Hungarica, Budapest, 2001, Vol. 36 (2), 231-243.
Rožić, N. (2003): Accuracy of geometric levelling networks at the terrritory of Croatia. Mitteilungen des
Bundesamtes für Kartographie und Geodäsie, Band 29, EUREF Publication No. 12, Frankfurt am
Main, 2003, 336-340.
Rožić, N. (2003a): Studija odnosa uporabnih visina repera geometrijskog nivelmana uvjetovanih
razlikama službenog i prijedloga novog visinskog sustava Republike Hrvatske. Geodetski fakultet
Sveučilišta u Zagrebu, Zagreb, 2003.
Rožić, N., Feil, L., Pavičić, S. (2000): Review of activities on levelling works in the Republic of Croatia
1999-2000. Veröffentlichungen der Bayerischen Kommission für die Internationale Erdmessung
der Bayerischen Akademie der Wissenschaften, Report on the Symposium of the IAG
Subcommission for Europe (EUREF) held in Tromsø, 22-24 June 2000, München, 2000, Heft Nr.
61, 362-365.
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- 80 -
EUROPEAN VERTICAL REFERENCE NETWORK (EUVN) CONSIDERING
CHAMP AND GRACE GRAVITY MODELS*
Željko Hećimović, Bojan Barišić, Ilija Grgić
ABSTRACT
European Vertical Reference Network (EUVN), solution UELN95/98, is compared with early
CHAMP (EIGEN-2, EIGEN-3p, TUM-1S, TUM-2Sp, ITG-CHAMP01E, ITG-CHAMP01S, ITGCHAMP01K) and GRACE (EIGEN-GRACE01S, GGM01S, GGM01C) gravity models. Besides CHAMP
and GRACE models Earth Gravity Model 1996 (EGM96) and European gravimetric geoid 1997 (EGG97)
are used in analysis. Comparisons are showing the main relation between EUVN datum and global
datum. Among used gravity models GRACE-GGM01C is the best fitting EUVN gravity field. It has only
slightly worst statistical characteristic than EGM96 model. GRACE-GGM01C model and EGM96 are
used to check extreme values in EUVN network. They are compared with already published EUVNEGG97 extreme values. To judge topography gravity signal in CHAMP and GRACE gravity models, they
are compared with denser field of GPS/leveling points on the local Croatian territory.
1. INTRODUCTION
CHAMP and GRACE satellite missions and further GOCE mission are strongly influencing
developments of geosciences in this decade. Already made CHAMP and GRACE gravity models are
defining new standards in modeling gravity field of the Earth. Gravity signal that was out of sensitivity of
previous satellite measurement techniques is clearly recognized. CHAMP and GRACE homogeneous,
almost global high-resolution satellite gravity data are mainly going to improve long and middle wave
gravity field spectrum. They are going to influence determination of vertical datum and heights networks.
EUVN network is giving opportunity to compare its GPS\leveling undulations with global geoids.
Wavelengths of a global geoid longer than the testing area (EUVN network) cannot be recognized, and
the shortest wavelengths of global model that can be checked depend how dens and how accurate are
the GPS\leveling undulations. Considering CHAMP and GRACE gravity models, distribution of
GPS\leveling undulations should be global and dense enough that weakest gravity signal in model can
be recognized.
2. USED DATA AND CHAMP AND GRACE GRAVITY FIELD MODELSEUVN network solution EUVNUELN95/98 (United European Leveling Network 1995/1998) is used (Ihde et al., 2002, Ihde and Sacher
2002a, Ihde and Sacher 2002b). It is related to the Normal Amsterdam’s Peil (NAP), but for islands and
countries not connected to UELN, the heights are given in local system. EUVN network have 186 points,
and distances between them are too big for reliable higher accuracy gravity field recovering. To have
overview of gravity field concerning only EUVN network, GRACE-GGM01C model is calculated only in
EUVN points. It is presented on the figure 1.
Fig. 1 GRACE-GGM01C gravity model in EUVN points.
održanom u Bratislavi, Slovačka, 2.-5.6.2004. godine. Objavljeno u Zborniku radova Simpozija (u tisku).
*
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In the analysis are used early CHAMP and GRACE models that include also some preliminary
solutions (s. table 1).
Table 1. The main characteristics of used global gravity models
Model
Max.
degree
MISSION
References
EIGEN-2
EIGEN-3p
TUM-1S
TUM-2Sp
140
140
60
60
CHAMP
CHAMP
CHAMP
CHAMP
Reigber et al., 2003b
Reigber et al., 2003c
Földvary et al., 2003a
Földvary et al., 2003b
ITG-CHAMP01E
75
CHAMP
Ilk K.H. et al., 2003,
Mayer-Gürr, et al., 2004
ITG-CHAMP01S
70
CHAMP
Ilk K.H. et al., 2003,
Mayer-Gürr, et al., 2004
ITG-CHAMP01K
EIGEN-GRACE01S
GGM01S
GGM01C
EGM96
70
140
120
200
360
CHAMP
GRACE
GRACE
GRACE
Ilk K.H. et al., 2003
GFZ, 2003
Tapley et al., 2003
UTEX, 2003
Lemoine et al., 1998
3. COMPARISONS OF EUVN AND CHAMP AND GRACE GRAVITY MODELS
To estimate how well CHAMP and GRACE geopotential models fit EUVN gravity field, they are
compared with EUVN GPS/leveling undulations. Besides used CHAMP and GRACE models Earth
Gravity Model 1996 (EGM96) and European Gravimetric Geoid 1997 (EGG97) are used. On the figures
2 and 3 differences between EUVN and EGM96 and EGG97 models are presented. Global gravity model
EGM96 is developed up to degree and order 360 using also terrestrial data, and EGG97 model is
regional European model that is using detail regional data. CHAMP and GRACE models are satellite
models, and they do not contain higher resolution, terrestrial gravity field information. Considering in
modeling used data, EGM96 and EGG97 models can be seen as referent models.
Fig. 2 Differences of EUVN and EGM96.
Fig. 3 Differences EGG97 and EUVN.
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On the figures from 4 to 13 differences between EUVN and early CHAMP and GRACE models
are shown. Local characteristic of differences can be clearly recognized, especially in CHAMP models.
Fig. 4 Differences of EUVN and EIGEN-2.
Fig. 5 Differences of EUVN and EIGEN-3p.
Fig. 6 Differences of EUVN and TUM-1S.
Fig. 7 Differences of EUVN and TUM-2Sp.
- 83 -
Fig. 8 Differences of EUVN and ITG-CHAMP01E.
Fig. 9 Differences of EUVN and ITG-CHAMP01S.
Fig. 10 Differences of EUVN and EIGEN-GRACE01K.
Fig. 11 Differences of EUVN and EIGEN-GRACE01S.
- 84 -
Fig. 12 Differences of EUVN and GGM01S.
Fig. 13 Differences of EUVN and GGM01C.
The main statistical characteristics are given in table 2. GRACE models fit EUVN gravity field
better than CHAMP models. That was expected considering differences in gravity field signal sensing
technique using CHAMP and GRACE satellite missions (GFZ, Daimler Chrysler Aerospace and
Deutsche Zentrum für Luft- und Raumfahrt 2000, Lühr et al. 2002, Neumayer et al. 2000, Reigber et al.
2001, Reigber et al. 2002, Reigber et al. 2003a, Reigber et al. 2003b, Baguio et al. 2002, JPL 2002a,
JPL 2002b, Tapley and Reigber 2002, Hećimović and Bašić 2004b, Hećimović and Bašić 2004c,
Hećimović and Bašić 2004d).
Average values of EUVN and CHAMP and GRACE undulation differences can be seen in the
first approximation as datum differences between EUVN network and global gravity models, but before
datum analysis extreme values should be treated. Dissipate this problem it is significant that EUVN
datum is lower than all global gravity models. Considering the quality of data used in the analysis, it can
be only judged that datums differences is about 0,5 m. EGG97 datum was fitted to EUVN heights datum
and that is the reason that average value is only -2 cm.
Table 2. The main statistical characteristics of EUVN and CHAMP and
GRACE undulations differences (186 points)
MODEL
Min.
Max.
Average
St. dev.
EGG97
EGM96
EIGEN-2
EIGEN-3p
TUM-1S
TUM-2Sp
ITG-CHAMP01E
ITG-CHAMP01S
ITG-CHAMP01K
EIGEN-GRACE01S
GGM01S
GGM01C
[m]
-1.51
-2.54
-3.87
-3.15
-3.85
-3.81
-3.34
-3.84
-3.66
-3.84
-2.76
-2.28
[m]
1.57
1.14
6.63
6.24
6.82
7.22
6.85
6.43
6.35
6.43
4.22
1.74
[m]
-0.02
-0.60
-0.45
-0.47
-0.42
-0.39
-0.45
-0.47
-0.43
-0.47
-0.51
-0.64
[m]
0.36
0.46
1.61
1.34
1.60
1.60
1.38
1.42
1.47
1.42
0.93
0.55
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Among used models GRACE model GGM01C is fitting EUVN gravity field the best. It can be
compared with EGM96 model that is developed up to degree 360.
In Ihde et al. (2002) EUVN extreme values (> 0,5 m) are found using EGG97 model. Similar
analysis is done using GRACE-GGM01C and EGM96 models. In table 3 are EUVN points with extreme
differences found with EGG97 (Ihde et al. 2002), EGM96 and GRACE-GGM01C gravity models. EGG97
model detected 17 points as extreme values, EGM96 model 31 points and GRACE model GGM01C 47
points. On the figure 14 are presented EUVN points with extreme values.
Table 3. EUVN points with extreme values found with EGG97 (Ihde et al. 2002),
EGM96 and GRACE-GGM01C models
Fig. 14 EUVN points with extreme values found with EGG97, EGM96 and GRACE-GGM01C models.
- 86 -
Five points are recognized as extreme values only by EGG97 and not by EGM96 and GGM01C
models; that was not expected.
5. CHECKING OF CHAMP AND GRACE GRAVITY MODELS USING DENSER FIELD OF GPS/
LEVELING POINTS ON THE LOCAL CROATIAN TERRITORY
EUVN network has only 186 points for the whole European territory, and the short-wave
structure of gravity field can be recognized only discretely in EUVN points and not on the whole
European territory.
To get better view in finer structure of gravity signal sensed with CHAMP and GRACE satellite
missions, 121 GPS/leveling points homogeneously distributed over the territory of Croatia are used. They
are compared with CHAMP-EIGEN-3p and GRACE-GGM01C models. Differences between
GPS/leveling and CHAMP-EIGEN-3p undulations are presented on the figure 15 and on figure 16 are
presented differences with GRACE-GGM01C model. In table 4 are the main statistical characteristics for
the both models (Hećimović and Bašić 2004a).
Fig. 15 Differences between GPS/leveling undulations and
undulations of CHAMP-EIGEN-3p model.
Fig. 16 Differences between GPS/leveling undulations
and undulations of GGM01C model.
- 87 -
Table 4. The main statistical characteristics of global geopotential model
on the territory of Croatia (121 points)
MODEL
Min.
Max.
Average
St. dev.
EIGEN-3p
GGM01C
[m]
-3.40
-2.02
[m]
1.89
0.17
[m]
-1.07
-1.00
[m]
1.04
0.45
The main characteristics of the Croatian topography is that dominating higher part is spreading
along the coast, and small higher part is in the middle of north-east Croatia, see figure 17. On the
Croatian coast mountains are rising very speedy from sea level up to 1500 m and higher.
Fig. 17 Croatian topography.
Comparing figures 15, 16 and 17 correlation with topography can be recognized in CHAMP
model. CHAMP undulations do not contain detail topography signal that is contained in GPS/leveling
undulations. The same effect cannot be found in GRACE undulations because they contain more
topography gravity signal and differences are less correlated with topography.
Average values in table 4 are in the first approximation datum difference between Croatian
heights system and EIGEN-3p and GGM01C global models. These values are showing agreement with
previously made comparisons between Croatian height system and EGM96 and GFZ97 global gravity
models (Hećimović and Bašić, 2002).
Because too large distances between points the same effect cannot be recognized in EUVN
network. Densification of EUVN points is necessary for regional and local improving and checking of
global gravity field models. That is topics of presently running EUREF EUVN_DA project.
5. CONCLUSIONS
Early CHAMP and GRACE gravity models used in comparison with EUVN network are showing
that EUVN datum is lower than datums of all global gravity models. Considering the quality of data used
in the analysis, it can be only judged that datums difference is about 0,5 m.
GRACE models show better fitting of gravity field than CHAMP models. Among used models GRACE
GGM01C model is fitting EUVN gravity field the best. It can be compared with EGM96 model that is
developed up to degree 360.
- 88 -
The biggest number of extreme values of undulation differences is found for GGM01C, after that
for EGM96 and finally for EGG97 model. That is also indicating quality relation between gravity models.
That was expected considering data used in modeling. It is surprising that some extreme values are
recognized only by EGG97 and not by EGM96 and GGM01C models.
Comparison of 121 GPS/leveling points homogeneously distributed over the territory of Croatia
and CHAMP-EIGEN-3p and GRACE-GGM01C models is indicating amount of topography gravity signal
sensed in CHAMP and GRACE models.
Full contribution of CHAMP and GRACE models can be expected in the future, especially
models that will combine CHAMP and GRACE satellite data with terrestrial data.
CHAMP is German satellite mission, GRACE USA/German and GOCE is ESA satellite mission.
These satellite missions are strongly influencing development of gravity field modeling community in
Europe. EUREF is fundamentally defined in domain of GNNS satellite radio navigation, but it has interest
in the Earth gravity field, and this gravity field trend in Europe is going to influence EUREF.
REFERENCES
Baguio, M., B. Bandeen, C. Griner, M. King i M. Srinivasan (Eds.) (2002): GRACE, Gravity Recovery and
Climate Experiment (GRACE) mission. NASA, Goddard Space Flight Center, Greenbelt,
Maryland, NP-2002-2-427-GSFC.
Földvary, L., Svehla, D., Gerlach, Ch., Wermuth, M., Gruber, T., Rumme, R., Rothacher, M.,
Frommknecht, B., Peters, T, Steigenberger, P. (2003a): Gravity Model TUM-2Sp Based on the
Energy Balance Approach and Kinematics CHAMP Orbits; Proceedings "Second CHAMP
Science Meeting", GFZ Potsdam, Sept. 1-4 (in preparation).
Földvary, L., Svehla, D., Gerlach, Ch., Wermuth, M., Gruber, T., Rumme, R., Rothacher, M.,
Frommknecht, B., Peters, T, Steigenberger, P. (2003b): Gravity Model TUM-2Sp Based on the
Energy Balance Approach and Kinematics CHAMP Orbits; Proceedings "Second CHAMP
Science Meeting", GFZ Potsdam, Sept. 1-4 (in preparation)
GFZ, DaimlerChrysler Aerospace i Deutsche Zentrum für Luft- und Raumfahrt a.V. (2000): CHAMP - Der
Blick in das Innere der Erde. 2000.
GFZ (2003): First GFZ GRACE gravity field model EIGEN-GRACE01S released on July 25, 2003.
URL:http://op.gfz-potsdam.de/grace/results/grav/g001_eigen-grace01s.html
Hećimović, Ž., T. Bašić (2002): Globalni geopotencijalni modeli na teritoriju Hrvatske. Geodetski list,
God. 57 (80), broj 2, str. 73-89, Zagreb 2003 (in Croatian).
Hećimović, Ž., T. Bašić (2004a): Comparison of CHAMP and GRACE geoid models with Croatian
HRG2000 geoid. 1st General Assembly European Geosciences Union (EGU), Nice, France,
from 25 - 30 April 2004. Poster presentation. Geophysical Research Abstracts, Vol. 6, 02715,
2004. SREef-D: 1607-7962/EGU04-A-02715. European Geoscience Union 2004.
Hećimović, Ž., T. Bašić (2004b): CHAllenging Minisatellite Payload (CHAMP) satelitska misija. Given for
publishing in Geodetski list (in Croatian).
Hećimović, Ž., T. Bašić (2004c): Gravity Recovery and Climate Experiment (GRACE) satelitska misija.
Given for publishing in Geodetski list (in Croatian).
Hećimović, Ž., T. Bašić (2004d): Gravity Field and Steady-State Ocean Circulation Explorer (GOCE)
satelitska misija. Given for publishing in Geodetski list (in Croatian).
Ihde, J., M. Sacher (Eds.) (2002a): European Vertical Reference Network (EUVN). Vol. I. Final
Documentation. Mitteilungen des Bundesamtes fuer Kartographie und Geodaesie. International
Association of Geodesy, Section 1 - Positioning, Commission X - Global and Regional Geodetic
Networks, Sub-Commission for Europe (EUREF). Publication No. 11, Vol. I. Frankfurt am Main
2002.
Ihde, J., M. Sacher (Eds.) (2002b): European Vertical Reference Network (EUVN). Vol. II. Final
Documentation. Mitteilungen des Bundesamtes fuer Kartographie und Geodaesie. International
Association of Geodesy, Section 1 - Positioning, Commission X - Global and Regional Geodetic
Networks, Sub-Commission for Europe (EUREF). Publication No. 11, Vol. I. Frankfurt am Main
2002.
Ihde, J., J. Adam, W. Gurtner, B. G. Harrson, M. Sacher, W. Schlueter, G. Woeppelmann (2002): The
Height Solution of the European Vertical Reference Network (EUVN). In: Ihde, J. A. Sacher
(2002): European Vertical Reference Network (EUVN). Final Documentation. Mitteilungen des
Bundesamtes fuer Kartographie und Geodaesie. International Association of Geodesy, Section 1
- Positioning, Commission X - Global and Regional Geodetic Networks, Sub-Commission for
Europe (EUREF). Publication No. 11, Vol. I. Frankfurt am Main 2002.
Ilk, K.H., Mayer-Gürr, T., Feuchtinger, M. (2003): Gravity Field Recovery by Analysis of Short Arcs of
CHAMP, Proceedings of the 2nd Science Workshop of CHAMP, accepted for publication.
- 89 -
JPL (2002a): Scientists Say 'Grace' as Water-Sensing Satellite Lift Off. JPL News (17.3.2002.).
JPL (2002b): Satellites Reveal Mystery of Large Change in Earth's Gravity Field (5.8.2002.).
Lemoine, F. G., Kenyon, S. C., Factor, J. K., Trimmer, R.G., Pavlis, N. K., Chinn, D. S., Cox, C. M.,
Klosko, S. M., Luthcke, S. B., Torrence, M. H., Wang, Y. M., Williamson, R. G., Pavlis, E. C.,
Rapp, R. H., Olson, T. R. (1998): The Development of the Joint NASA GSFC and the National
Imagery and Mapping Agency (NIMA) Geopotential Model EGM96. Greenbelt, Maryland 20771.
Lühr, H., L. Grunwaldt i Gh. Förste (2002): CHAMP Reference Systems, Transformations and Standards.
GFZ Potsdam 2002.
Mayer-Gürr, T., Ilk, K.H., Eicker, A., Feuchtinger, M. (2004): ITG-CHAMP01: A CHAMP Gravity Field
Model from Short Kinematical Arcs of a One-Year Observation Period, submitted to Journal of
Geodesy.
Neumayer, K. H., S. Y. Zhu, C. Reigber, R. König i H. Meixner (2000): CHAMP Orbit Recovery Algorithmic Approaches and Preliminary Results. http://op.gfz-potsdam.de/champ/ 2000.
Reigber, C., H. Lühr i P. Schwintzer (2001): Announcement of Opportunity for CHAMP.
GeoForschungZentrum Potsdam, Potsdam 2001.
Reigber, Ch., Balmino, G., Schwintzer, P., Biancale, R., Bode, A., Lemoine, J.-M., Koenig, R., Loyer, S.,
Neumayer, H., Marty, J.-C., Barthelmes, F., Perosanz, F., Zhu i S. Y. (2002): A high quality
global gravity field model from CHAMP GPS tracking data and Accelerometry (EIGEN-1S).
Geophysical Research Letters, 29(14), 10.1029/2002GL015064, 2002.
Reigber, C., H. Lühr i P. Schwintzer (Eds.)(2003a): First CHAMP Mission Results for Gravity, Magnetic
and Atmospheric Studies. Springer-Verlag. Berlin, Heidelberg, New York 2003.
Reigber, Ch., Schwintzer, P., Neumayer, K.-H., Barthelmes, F., König, R., Förste, Ch., Balmino, G.,
Biancale, R., Lemoine, J.-M., Loyer, S., Bruinsma, S., Perosanz, F., Fayard, T. (2003b): The
CHAMP-only Earth Gravity Field Model EIGEN-2. Advances in Space Research 31(8), 18831888 (doi: 10.1016/S0273--1177(03)00162-5).
Tapley, B., Ch. Reigber (2002): GRACE Newsletter, No, GFZ, CSR, DLR, NASA.
UTEX (2003): GRACE Gravity Model 01 - Released July 21, 2003. URL: http://www.csr.utexas.edu/
grace/gravity/.
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TOPOGRAPHIC DATA PRODUCTION AS BASIS FOR NSDI –
CROATIAN EXAMPLE*
Stipica Pavičić, Mladen Rapaić, Slavko Lemajić
ABSTRACT
The establishment of the Croatian National Spatial Database Infrastructure have started at the
beginning of the 1990's. At the front of the activities was the State Geodetic Administration that gathers
surveying and geodetic experts from geodetic companies, science and educational organizations. They
built the basic documentation that designates vision and goals, while through studies and pilot projects
they developed procedures and exact steps for realization of the goals. SGA by definition and it's internal
structure does not have capacities for production of geodetic products, so all production phases are
commended to the private geodetic companies in public and open tenders.
One of the basic tasks in creation of NSDI is establishment of the Topographic Database,
detailed and accurate spatial and seamless database of Croatia that has to serve for wide spectrum of
users, from state and local administration, public institutions and state companies to the private
companies. The main source for Topographic Database are topographic data collected in systematic and
coordinated process by private geodetic companies. By establishment of the Croatian Geodetic Institute
the process of Quality controlling the topographic data ensures the homogeneity and alignment of the
data to the Product Specifications that serves as a standard in production processes.
In front of the geodetic community in Croatia are some important and inevitable steps that will
allow integration into the European geospatial system. First of all, the change of geodetic datum and
cartographic projection which have to be accommodated regarding new technologies and users' needs
and secondly, adoption of the ISO standards, the process that already started in State Office for
Standardization and Metrology.
KEYWORDS
NSDI, geoinformation, topographic database, quality control, ISO
1. INTRODUCTION
It is considered nowadays that one of the prerequisites for a country development is the
establishment of the National Spatial Database Infrastructure (NSDI). According to Federal Geographic
Data Consortium, NSDI implicates: technology, polices, standards and human recourses necessary to
acquire, process, store, distribute and improve utilization of geographic data. Republic of Croatia started
building its infrastructure soon after proclaiming independency, with the State Geodetic Administration
(SGA) in the forefront of activities, but structured and organized without own production and development
facilities. By the law and by the status, the SGA has that authority and responsibility and also acts as the
National Mapping Organization. In production of topographic data, the specific "Croatian model" (Rožić,
2003) can be recognized, the model that consists of triangle formed by SGA, the Croatian Geodetic
Institute and private geodetic companies who actually perform production. The aspect of this paper is
concentrated in description of the production process and quality control of topographic data that are
used for the Topographic Database uploading.
2. PREPARATORY ACTIVITIES
In the middle of the 1990's, the State Geodetic Administration established some of the
fundamentals for successful building of infrastructure needed for creation of geodetic products: legal
frame, reorganization of geodetic administration and delivery of Program of State Survey and Real
Estate Cadastre for the period 2001-2005 that was adopted by the Croatian Parliament and is financed
mainly through the State and local administrations' budgets. Major guidelines have been created in
cooperation with the experts from the major private companies and from the Faculty of Geodesy (Bačić,
2003). The project STOKIS (Official Topographic and Cartographic Information System of the Republic of
Croatia) from 1992 was the basic, general document for creation of digital topographic data. The
Predstavljeno na "FIG Working Week 2004" održanom u Ateni, Grčka, 22.-27.5.2004. godine. Dostupno
na CD-ROM mediju (Conference proceedings, ISBN 87-90907-30-2, International Federation of
Surveyors, 2004) i Internet stranici skupa www.fig.net/pub/athens/programme.htm.
*
- 91 -
following project CROTIS (Croatian Topographic Information System) gave more specific, implementable
instructions for production and processing.
The fundamental geodetic legislative document, Law on State Survey and Real Estate Cadastre,
delivered by the Croatian parliament in 1999 became fundament for the set of law's and bylaw's
regulations, such as Ordinance on Topographic Survey Methods and State Map Production, Guidelines
for Orthophoto Production, Mapping Catalogue, Cartographic Key, Guidelines for Aerial Photography,
Cartographic Generalization with Standardisation for State Maps and others.
The first projects were started with the basic scope to overcome technology challenges and to
proof the ideas written in previously made documentation. The first products have been very often
analogue, but the production processes were more and more managed with the modern, digital
equipment. One of the first realized projects that had and still has great influence in further development
was cyclic aerial photographing of the whole country (56000 sq km) in scale 1:20000 (Figure 1).
Scanning those films with photogrammetric scanner, State Geodetic Administration built the basic source
for products such as Digital Orthophoto, Digital Terrain Model and Topographic Data.
The crucial support and push in the same time, SGA received from the Croatian parliament in
the form of Program of State Survey and Real Estate Cadastre. Some of the tasks that Croatian
geodesist have to achieve in the field of topography, are (Official Gazette, 2001):
- production of all 603 map sheets of Topographic map 1:25000 (TK25)
- maintaining the cyclic aerial photographing of the country in five years time-frame (20% per year)
- finishing the project of Croatian Base Map 1:5000 (HOK) that started more than 30 years ago
- conversion of all map sheets (approx. 10000) of HOK into digital format
- creation of 5000 (50%) map sheets of Digital Orthophoto 1:5000 (DOF)
- foundation of digital Registry of Administrative and Spatial Units and
- establishment of multipurpose spatial information system for supporting the state and the local
administration and public institutions in land management.
Fig. 1 Overview map of realisation of cyclic aerial photographing project (State Geodetic
Administration, 2003c)
Finally, by establishing the Croatian Geodetic Institute (CGI), new institution completely
independent in commercial and technological aspects, the State Geodetic Administration acquired the
partner (and the tool) for developing and conducting quality control processes of the geodetic products
as well as scientific and professional support. The CGI enabled the processing circle of production of
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geodetic products to be fully closed. The CGI defines the "Croatian model" (Rožić, 2003), the framework
for clear and undoubtfull duties and responsibilities in the production of national topographic,
cartographic and other geodetic products which, besides SGA and CGI, consists of private geodetic
companies to whom the whole production is commended. The first tasks of the Institute have been
design and execution of the Quality System for newly created Topographic maps 1:25000. In
continuation, the work expands on design and execution of quality controls for other geodetic products
such as Topographic Data, Orthophoto, Aerial Photographs, etc.
3. PRODUCTION OF TOPOGRAPHIC DATA
Previous activities, for the first time after the independence, enabled the geodetic community in
Croatia to be in the position to launch the national project that will methodically cover whole country
territory in homogenous, standardised way. After establishing the basic prerequisites, general plan was
made that promotes topographic data production. Figure 2 shows basic responsibilities and steps and
Figure 4 shows details of work that is done during data collection phase within geodetic companies.
Fig. 2 Production of topographic data
The objective of the program of topographic data production is the seamless Topographic
Database (TdB) with positional accuracy of +/-1m on well defined details and +/-3m on other details
(State Geodetic Administration, 2001b). By its content and accuracy, the database will be more than
appropriate for production of Topographic map 1:25000. Although the data could be used for map
production of larger scales (e.g. 1:10000), it is not considered because of the SGA's policy of creation
and maintaining the serials of maps in scales 1:5000, 1:25000, 1:50000, 1:100000 and 1:200000. The
data should fulfill the wide needs of a different users, from infrastructure object designers and urban
planners to the professionals in a local community administration. Data should enable presentation of
topographic objects in three dimensions, should be structured logically for the simplicity of acquisition,
and the aerial images produced in the on-going project of cyclic aerial photographing have to be used as
the main source. The complete production process (except aerial photographing) was put in the hands of
several largest private geodetic companies and for assuring the homogeneity of quality and for enabling
the automated procedures in certain production steps, it was inevitable to prepare very detailed
standards and directions for all production phases.
The standardisation of the production process was accomplished in the frame of the CroatianNorwegian Geoinformation project (CRONO-GIP) which goal was "development and implementation of a
database within SGA for storage and use of data resulting from the on-going production of new
topographic maps in the scale 1:25000" (Rožić et al, 2003). The project was conducted by SGA and CGI
and realised in cooperation with Norwegian consulting company Program Management & Mapping along
with Croatian geodetic professionals gathered around the Geofoto company. The existing production
process was separated into fundamental phases and the result of each phase can be treated as standalone geodetic product: (1) Aerial Photography and Ground Control, (2) Scanned Photo, (3) Aerial
Triangulation, (4) Digital Terrain Model, (5) Orthophoto, (6) Topographic Data and (7) Topographic Map
1:25000.
In the same time, each of the Products serves as the predecessor for the following production
phase (Figure 3) so that each company can be in state to undertake and proceed the job from any other
company. Two "main" products are needed for creation of Topographic Database: Topographic Data
(TD) and Digital Terrain Model (DTM) and for their production, the Aerial Triangulation is the
predecessor. It is planned that each production step in form of the Product will have to be quality
controlled and approved before further usage.
Although "main", only those Products are not foreseen to be on the market. Instead, the "export"
from Topographic Database will be offered. The Product Topographic map 1:25000 is at the end of the
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process line and it represents "derived" product from TdB which may, in the future, become optional as
soon as all 600 map sheets are done in the first edition.
Fig. 3 Products and products' predecessors
Standardisation of the Products is coming out of the Product Specifications that exist in the form
of documentation and appropriate analogue and digital appendices. Specifications are designated with
the exact version number and, generally, contain following information and instructions:
- description and purpose of the Product
- common set of terms (Terminology)
- data sources, including obligatory predecessors
- geographic coverage
- coordinate reference systems (horizontal and height)
- description of delivery which at least has to have (1) delivery list, (2) Product itself and (3)
Technical Report
- required content of Technical Report
- Products in digital format has to be defined for file format and file arrangement and naming
- technical characteristics of the Product
- technical characteristic of the equipment used in production process
- technical description of the production process
- parameters for evaluation of Product's quality
- all other relevant information and instructions needed for production (for example, in Technical
Specification for Topographic map 1:25000, the appendices (1) Generalisation, (2) Cartographic
Key and (3) Map Nomenclature and Names are added).
The greatest efforts have been embedded in creation of the specifications for Topographic Data
and Topographic Map because the subjective factor has greatest influence during photogrammetric
mapping, field data collection, generalisation and cartographic design processes. Specifications are
constituent part of the Contract between the State Geodetic Administration and the Producer (private
geodetic company).
The structure of topographic data is defined by the project Croatian Topographic Information
System (CROTIS). Taking into consideration that almost all companies use CAD tools for the
photogrammetric data collection, the Mapping Catalogue was created that uniquely defines each feature
class by the unique combination of graphic attributes Level, Color, Line Style and Weight, as shown in
Table 1 (State Geodetic Administration, 2001a). The Catalogue also defines type of the geometry for
feature representation, symbol name for point features and name of the table in the Access database
that contains related metadata and attributes. The Mapping Catalogue is constitutional part of the
Topographic Data (TD) specification.
For undoubtful, unique and homogeneous way of transforming topographic objects in stereomodel to the primitive geometric elements in CAD and for unique attributisation, TD specification
contains very detailed instructions called Data Capture Object Selection Criteria that explains
topographic objects' definitions, presentation manners and priorities with examples.
The result of photogrammetric measurement is completed with data from other sources as well
as information (mostly attributes) collected on the field. In the next step, those "raw" data are separated
into several files for further compilation. Geometry is connected with the appropriate rows in the
appropriate tables. Buildings and land cover are layers that must be topologically correct before
uploading into the Topographic Database. To accomplish that requirement, two sets of data must be
created: (1) building data compiled from building lines and classification codes related to buildings and
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(2) land cover data compiled from land cover lines and classification codes related to land cover.
Companies must clean linear networks in those datasets and establish topology relationship of
classification codes to polygon areas.
Table 1. Excerpt form Mapping Catalogue that defines unique definition of certain
features in Feature group Electric Power System
3100 ELECTRIC POWER SYSTEM
DATABASE TABLE
UTILITY LINES
U_META
UTILITY LINES SINGLE ELEMENTS
U_META
LV
CO
ST
WT
3101 ELECTRIC POWER SUPPLY LINES
Line
AERIAL LINE
11
0
0
0
UNDERWATER LINE
11
16
2
0
LV
CO
ST
WT
CELL
Point
3102 SINGLE POWER SUPPLY LINE ELEMENTS
METAL POLE
17
0
0
0
3102B
CONCRETE POLE
17
0
0
0
3102C
The Digital Elevation Model (DEM) must be interpolated and delivered in the form of regular grid.
The input data are height points, formlines and natural break lines merged with break lines from the land
cover data set (road edges, river banks, etc.) (State Geodetic Administration, 2003b).
Final data must be delivered, according to the specifications for Topographic Data and Digital
Terrain Model in five MicroStation design files, one Access database and one text file (Figure 4).
Fig. 4 Production of topographic data – acquisition, processing and delivery
4. QUALITY CONTROL SYSTEM
After Topographic Data and Digital Terrain Model delivery (Figure 4) the process of Quality
Control in Croatian Geodetic Institute starts (Figure 5).
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Fig. 5 Controlling and database uploading procedure
According to definitions of ISO quality elements, subelements, descriptors, evaluation methods
and selected tolerances (ISO, 2001) the Quality Plan is developed. Execution of the Quality Plan on
Topographic Data and DTM results with the Quality Evaluation Reports.
Short simplified overview of Topographic Data quality control elements and subelements is
presented in Table 2.
Table 2. Quality elements and subelements used for Topographic Data quality control
(State Geodetic Administration, 2003a)
ISO Quality Element
Quality
Subelement
Overview
Configuration
Spatial
Characteristics
History
HW and SW
description
Model
Configuration
Completeness
Commission
Omission
Logical Consistency
Domain
Consistency
Check …
- That all items are delivered
- Readability of digital media
Approval of predecessors
Producer’s information about hardware/software,
calibrations, certificates, licenses, etc.
Check interior orientation number of fiducial marks
used
For analytical plotters, check number of control
points/passpoints used for model orientation and their
distribution in the model
Model orientation error
Model orientation gross errors > 3* SD
Excessive objects
Buildings
Utility lines
Transportation
Hydrography
Vegetation and land use
Toponyms
Feature classes, attributes and values
- 96 -
ISO Quality Element
Quality
Subelement
Format
Consistency
Geometric fidelity
Thematic Accuracy
Positional Accuracy
Topological
Consistency
Classification
Correctness
Absolute
Accuracy
Check …
- That correct file-naming conventions are used
- That MicroStation v7 format is used and with
parameters according to product specification
- That MS Access v2000 is used
- That data contains only points, linestrings and text
objects
- That dataset has correct topology
- Dataset
Well defined details
Not well defined details
Gross errors > 3* SD
The process of quality control procedures can be divided in four classes depending of the control
type used: manual full (MF), automatic full (AF), manual sample (MS) and automatic sample (AS).
Automatic sample control is not included in the CGI quality system procedure. In following
chapters the applications of full manual, full automatic and sample manual quality control procedures
used in control of Topographic Data are described.
4.1. FULL MANUAL QUALITY CONTROL PROCEDURES
Full manual controls are used to check all items identified for the Overview quality element. It
has to be manually checked that all expected documents and files are delivered, that the CD media is
usable and the files are named according to the Specification (subelement Configuration).
The subelement History assures that all predecessors (Figure 3) have been approved. For
Topographic Data it has to be checked that product Aerial Triangulation is approved and if the data were
produced using scanned photos, the Scanned Photo have to be approved first. To execute this step of
control process the contractor have to identify the SGA/CGI's project number and the name of
predecessor products, as well as the date for submission of these products to CGI for quality control.
Last identified subelement of the Overview quality element is HW and SW description. This
subelement requires brief and concise description of hardware and software used in the production. The
criteria for acceptance is that the instrument calibration Report is according to the Specification and the
vendor name, version number, main purpose of the SW/HW and the technical capabilities for the job are
provided.
Manual control is also used to check some of the items belonging to quality elements
Completeness and Logical consistency. It has to be checked that there is no objects (data) outside of the
production area and that the landcover polygons are closed to the production area boundary
(subelement Commission). Omission of special objects and omission of the settlement names have to be
checked with zero tolerance, but the toponyms of significant hydorographic objects are checked with the
different specified tolerance.
Domain consistency and the Format consistency are the last two subelements belonging to the
quality element Logical consistency that have to be checked in full manual manner, both with zero
tolerances. Checking domain, controller have to verify that there is no new, undefined attribute values in
Access database and checking format, controller have to verify that all dgn files are version 7 and are
readable in MicroStation and that Access mdb file is version 2000 and is readable in MS Access.
4.2. FULL AUTOMATIC QUALITY CONTROL PROCEDURES
Full Automatic method in quality control procedure is done with the use of FME (Safe Software
Inc.) Workbench files developed firsty under the CRONO GIP project and later in the Croatian Geodetic
Institute. A number of quality elements are checked in this way all with zero tolerances. Automatic control
is performed after manual control of all items belonging to the Overview quality element.
FME Workbench files are designed to detect anomalies in deliverd dgn files relating to Product
Specification. Following simple procedure, the controller can detect variety of errors. It can be detected if
the object is below minimum size (subelement Minimum Size). Minimum size is defined in Product
Specification for buildings (20 m2), landuse (500 m2) and utility lines (10 m). Checking Domain
Consistency it can be detected if the features are encoded according to the Product Specification. The
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allowed combinations of level, color, style and weight (example in Table 1) are checked in all dgn files. It
can also be detected if the classification text codes for future polygon construction (buildings, landuse
areas and elevated areas) are legal according to the Mapping Catalog.
Geometric representation in dgn files is also restricted by the Product Specification. Subelement
Geometric fidelity is checked for presence of undefined geometry. The only allowed geometry elements
are: text, point (cell) and the linestring.
Except of described subelements, the automatic control procedure is applied to check the
topological consistency. No features are allowed to intersect themselves in Utility, Buildings and
Landcover dgn files. Buildings and landcover boundaries are not allowed to cross each other, building
boundaries also should not cross landuse boundaries but elevated objects boundaries are allowed to
cross other boundaries. Each building, landuse and elevated object polygon must have just one
classification point. Automatic control reports if the classification points are multiple or missing. After
construction of closed polygons all dangling lines are detected for landuse, buildings and elevated areas.
If the automatic control procedure does not fail controller can go ahead with the rest of controlling
procedure. One small part of that procedure is presented in the Chapter 4.1. and the rest belongs to the
sample manual controlling procedure.
4.3. SAMPLE MANUAL QUALITY CONTROL PROCEDURES
Manual control is the most demanding part of quality control procedure. Majority of manual
control is done with sampling.
Some items belonging to the quality element Spatial Characteristics are checked during
automatic control procedure with the FME Workbench files (subelement Minimum Size) but the rest are
checked manually with sampling. Sample is used for Model Configuration sublement. Items belonging to
that quality subelement have to confirm that the minimum four fiducal marks have been used, that the
minimum six points are in Gruber positions and that at least four points are used for absolute orientation
of the photogrammetric model. The last item, dealing with Model Configuration that has to be checked is
Model Orientation Error. Maximum allowed standard deviation (SD) for model orientation error is set to
0.3 m. Gross errors, which are defined as 3 SD are not allowed.
Table 2. is simplified version of real quality control plan that has to be applied. For example,
tolerances for checking omission of buildings may not be universally set to some value because some
buildings can be treated more important then others. That is the reason why the item Buildings is further
divided into few sub-items with different tolerances: residential, not residential, point objects and other
objects. Besides omission of buildings, with sampling procedure, the omission of utility lines,
transportation, hydrography, the rest of landuse and the rest of toponyms are checked.
Most items belonging to the quality element Logical Consistency are checked without sampling.
Sampling procedure is applied to check correct spelling of toponyms (subelement Domain consistency)
and the proper snapping of road centerline network (subelement Topological consistency).
Thematic accuracy quality element is fully checked manually with sampling. This quality element
is in the Table 2 roughly presented using the only one quality subelement, Classification Correctness.
The real situation is that the dataset is checked with different tolerances dividing the whole dataset into
several items belonging to the Buildings, Utility lines and point features, Landuse, Transportation and the
Hydrography. Depending of the object significance different tolerances may be used. The main tool in
controlling is Digital Photogrammetric Workstation using the original photogrammetric material.
The rest of items that has to be checked belongs to the quality element Positional accuracy and
the quality subelement Absolute accuracy. For well defined details the tolerance is defined using
standard deviation of 1m and for not well defined details the tolerance is 2m.
Determination of number of objects in a sample is based on 95% confidence level. To help
controller in determination of number of objects in a sample, two statistical tables are made (Table 3).
Left table is used for sample based control of errors and missing objects and the right table is used for
sample based control of standard deviation. Values presented in table 3. are in conformance with ISO
2859 and ISO 3951.
Table 3. Statistical tables for sample size determination based on 95% confidence interval
For sample based control of errors and missing objects
For sample based control of standard deviation
Number of objects
Number of objects
From
To
Po (%) =
Sample
size
1.0
2.0
3.0
5.0
From
To
Sample
size
Fdistribution
1
8
all
1
1
1
1
1
26
all
1
9
50
8
1
1
1
1
26
50
5
1.54
51
90
13
1
2
2
3
51
90
7
1.45
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For sample based control of errors and missing objects
For sample based control of standard deviation
Number of objects
Number of objects
From
To
Po (%) =
Sample
size
1.0
2.0
3.0
5.0
From
Sample
size
To
Fdistribution
91
150
20
2
2
3
4
91
150
10
1.37
151
280
32
2
3
3
4
151
280
15
1.30
281
400
50
3
3
4
6
281
400
20
1.26
401
500
60
3
4
5
7
401
500
25
1.23
Po – tolerance from the Product Specification
4.4. REPORTING QUALITY CONTROL RESULTS
In the addition are presented excerpts from typical CGI tables planed for performing and
reporting quality control. Those tables as a templates are developed with the use of Microsoft Excel.
They are intended to guide the controller in controlling and reporting the quality of dataset. Abbreviations
used in following tables are: MF – manual full, MS - manual sample, AF – automatic full, AS – automatic
sample, E – Exclusive, Q – Quantitative, SD – standard deviation.
Table 4 Excerpt from CGI control items
ID
ISO Element
ISO
Subelement
Sc2
Spatial
characteristics
Model
configuration
Sc3
Spatial
characteristics
Model
configuration
Item
Distr. of
points
Model
orientation
error
Eval
Type
Ctrl
type
Tol%/
SD
Details about control item
E
MS
n/a
- minimum 6 in Gruber positions,
minimum 4 used for abs. orient.
E
MS
0.3
meter SD
…
Table 5 Excerpt from CGI quality control results
No
Of
Obj
Obj
In
Samp
Failed
object
s
Fail
%
Tol%
/
SD
95%
tol
Result
MS
n/a
n/a
n/a
n/a
MS
n/a
0.3
n/a
n/a
ID
Control Item
Eval
Typ
Ctrl
type
Sc2
Distribution of points
E
Sc3
Model orientation error
E
…
Table 6 Example of control details: Number of fiducial marks
CONTROL DETAILS
Quality control ID
ISO Subelement
Control Item
Control type
Result
Sc1
Model configuration
Number of fiducial marks
Manual-Sample
n/a
Remarks to control result:
Additional documentation / screenshots / listings / co-ordinates / …
Table 6 contains details of one particular control item. Typically there will be one similar table for
each failed control item in the quality control.
Reporting of Data Quality Evaluation can be done in different stiles (Lemajić, 2003) and for the
future reports CGI is planning to use presented tables (table 4, table 5 and table 6) with some additional
informations (dates of delivery and quality control, controller names, ...).
In the case of positive quality control result all of dgn files are converted in common coordinate
system and at the same time translated in FME format files (ffs). Features belonging to the same
CROTIS class and geometry type (area, line or point) form one ffs file. Each topographic feature gets in
this stage a "stamp" in form of attributes that denote the contract number (CONTRACT_ID) and quality
control identificator (QCID) and gives credit to the future users of Topographic Database that the
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received data is quality controlled. At the end of procedure all of the ffs files are uploaded into the SGA's
Topographic Database.
Working with real data and inspecting possibility of reaching certain level of quality will help CGI
experts to develop and implement more reliable quality system. Besides development of quality system,
performing quality control can emphasize weakness of the product specifications and help to make it
superior. Errors common to all producers points that something might be incorrectly described or be
impossible to achieve. In this early stage of developing the whole production process, it is extremely
important to act fast and coordinated between SGA, CGI and production companies in correcting and
upgrading product and quality documentations. The particular cases appeared at the first deliveries e.g.
the Specification did not foreseen that buildings can form closed polygon, which caused error in
automatic control processes. Such examples were solved in direct consultation with SGA and producers
and were noticed for change in future versions of Specification.
5. CONCLUSION
Republic of Croatia started many processes with the goal to create national spatial data
infrastructure. From the technical, technological, organisational, financial and implementable side those
processes are carried by experts from geodetic companies, science and educational organisations and
state bodies guided by the State Geodetic Administration.
Production of spatial data have started, first experiences enabled geodesists to improve
implemented documents and technology procedures. Very important part in the cycle of improvement
lies on the Croatian Geodetic Institute that controls most of the geodetic Products and is in position to
objectively evaluate the Products and its Specification in the same time. It has to be pointed out that the
Quality Control System acording to ISO norms is in process of development and implementation and stil
not routine. In spite of that, all of the Products are national official standardized products with State
warranty.
Geodetic community in Croatia still have the obligation to perform several important and
inevitable steps that will allow integration into the European spatial system. First of all, it is change of
geodetic datum and cartographic projection which have to be accommodated to new technologies and
users' needs and adoption of the ISO standards, the process that already started in State Office for
Standardization and Metrology.
REFERENCES
Bačić, Ž., 2003, Outsourcing whole production out of NMO: Croatia as an example, Cambridge
Conference, http://www.cambridgeconference2003.com
Federal Geographic Data Committee, http://www.fgdc.gov/nsdi/nsdi.html
ISO, 2002, ISO 2859 Sampling procedures for inspection by attributes
ISO, 2001, ISO 19113 Geographic information - Quality Principles, Draft International Standard, ISO
TC/211
ISO, 1989, Sampling procedures and charts for inspection by variables for percent nonconforming
Lemajić, S., Rožić, N., Rapaić, M., 2003, Improvement of Quality Control System in Croatia, Proceedings
of the ISPRS WG VI/3 Workshop 2003, 168-172, Zagreb, State Geodetic Administration and
Croatian Geodetic Society
Official Gazette, 2001, Program of State Survey and Real Estate Cadastre for the period 2001-2005, no
64, Zagreb
Rožić, N., 2003, Strategy and System of Quality Control of the Official Geographic Data produced by
Private Companies in Croatia, Cambridge Conference, http://www.cambridgeconference
2003.com
Rožić, N., Lemajić, S., Rapaić, M., 2003, Croatian-Norwegian geoinformation project, Proceedings of the
ISPRS WG VI/3 Workshop 2003, 224-227, Zagreb, State Geodetic Administration and Croatian
Geodetic Society
State Geodetic Administration, 2001a, Croatian Topographical Information System, ver. 1.1., Zagreb,
SGA
State Geodetic Administration, 2001b, Ordinance on Topographic Survey Methods and State Map
Production, Official Gazette, no 55, Zagreb
State Geodetic Administration, 2003a, Product Specification Topographic Data 1.0, Zagreb, SGA
State Geodetic Administration, 2003b, Product Specification Digital Terrain Model 1.0, Zagreb, SGA
State Geodetic Administration, 2003c, Catalogue of Products, Zagreb, SGA
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VISINSKA KONTROLA GEODETSKIH I KARTOGRAFSKIH PROIZVODA
U PROCESU TOPOGRAFSKE I KATASTARSKE IZMJERE*
Ilija Grgić, Bojan Barišić, Slavko Lemajić
SAŽETAK
Utemeljenjem Hrvatskog geodetskog instituta (HGI) kao javne ustanove za potrebe obavljanja
stručnih poslova sukladno Zakonu o državnoj izmjeri i katastru nekretnina (NN 128/99) stvorene su
pretpostavke za kontrolu kvalitete nacionalnih geodetskih i kartografskih proizvoda te za nadzor izvedbe
geodetskih radova. Raznim projektnim zadaćama definirana su određivanja i izračuni orijentacijskih
točaka za potrebe aerotriangulacije, u pravilu sa svim elementima kojih se proizvođač u procesu izrade
konačnog proizvoda mora pridržavati. U procesu izrade geodetskih i kartografskih proizvoda su do sada
proizvođači u pravilu računali normalne ortometrijske visine iz modela geoida ili koristeći
trigonometrijskim nivelmanom određene visine trigonometrijskih točaka. U ovom radu se želi pokazati na
temelju obavljenih kontrola kvalitete da li takav pristup, bez povezivanja određenog broja orijentacijskih
točaka na repere državne visinske mreže, može zadovoljiti unaprijed postavljene zahtjeve točnosti.
KLJUČNE RIJEČI
visinska kontrola, ISO, kontrola kvalitete, model geoida
ABSTRACT
Important event for quality control of national geodetic and cartographic products in Croatia was
establishing of Croatian Geodetic Institute as public institute. Main role of the Institute is to perform high
professional tasks according to the Law of state survey and real estate cadastre. Positioning of
aerotriangulation’s ground control points with all quality elements which must be followed by the producer
are defined within different project tasks. Usually in production of geodetic and cartographic products
normal ortometric heights are calculated from geoid model or by using heights of trigonometrical points
determined by trigonometrical levelling. This article describes comparison of heights determined by using
official geoid model and by geometric levelling to the nearest national vertical reference frame
benchmarks. Final result of this comparison will show which projects can use geoid model for heights
determination.
KEYWORDS
height control, ISO, quality control, geoid model
1. UVOD
Hrvatski geodetski institut (HGI) utemeljen je kao javna ustanova za potrebe obavljanja stručnih
poslova sukladno Zakonu o državnoj izmjeri i katastru nekretnina (NN 128/99), a njegovim utemeljenjem
su stvorene pretpostavke za kontrolu kvalitete nacionalnih geodetskih i kartografskih proizvoda te za
nadzor izvedbe geodetskih radova. Poslovi kontrole kvalitete obavljaju se za potrebe Državne geodetske
uprave (DGU) sukladno razvijenom sustavu kontrole kvalitete u HGI-u zasnovanom na ISO normama.
Uvažavajući činjenicu da je HGI u potpunosti osposobljen za obavljanje poslova kontrole kvalitete
geodetskih proizvoda koji su rezultat topografske i katastarske izmjere, HGI za potrebe DGU-a pruža
Tehničke usluge kontrole kvalitete TK25, digitalnih ortofoto karata u mjerilu 1:5000 i 1:2000 i ostalih
geodetskih i kartografskih proizvoda. Temeljna načela po kojima se obavlja kontrola kvalitete primarno
su određena odredbama Ugovora, projektnim zadatkom u cjelini, standardima i pravilima struke te
posebnim naputcima izdanim od DGU-a. Osim toga, dopunska osnova za obavljanje kvalitete sadržana
je u zakonima i važećim propisima te raspoloživim izvornicima. Sadržaj poslova kontrole kvalitete definira
elemente kvalitete, izvornike na temelju kojih će se kontrola obaviti te metodu pregleda. Distribucija
proizvoda koji su predmet obavljanja kontrole kvalitete vrši se posredstvom DGU-a, a rezultat obavljanja
kontrole kvalitete u HGI-u predstavljaju pisana izvješća koja se dostavljaju DGU-u na daljnje postupanje.
Projektnom zadaćom definirano je određivanje i izračun orijentacijskih točaka za potrebe
aerotriangulacije, u pravilu sa svim elementima kojih se proizvođač u procesu izrade konačnog proizvoda
Predstavljeno na Trećem hrvatskom kongresu o katastru s internacionalnim sudjelovanjem, održanom u
Zagrebu 7.-9.3.2005. godine. Objavljeno u Zborniku radova Kongresa (Grgić, I., Barišić, B., Lemajić, S.:
Visinska kontrola geodetskih i kartografskih proizvoda u procesu topografske i katastarske izmjere.
Zbornik radova, Treći hrvatski kongres o katastru s međunarodnim sudjelovanjem, Hrvatsko geodetsko
društvo, Zagreb, 2005, 337-343).
*
- 101 -
mora pridržavati. Orijentacijske točke određuju se u državnom koordinatnom sustavu geodetskim
metodama mjerenja i instrumentarijem koji preciznošću zadovoljava postavljene zahtjeve točnosti. O
obavljenim radovima radovima izrađuje se Elaborat određivanja orijentacijskih točaka, a oblik i sadržaj
Elaborata propisuje se projektnom zadaćom. Elaborat u cjelini i pojedinim dijelovima mora sadržavati sva
objašnjenja, informacije i podatke koji omogućuju neovisno ponavljanje radova posebno polazne
podatke, završne podatke, a po potrebi i međurezultate. U procesu izrade geodetskih i kartografskih
proizvoda su do sada proizvođači u pravilu računali normalne ortometrijske visine iz modela geoida ili
koristeći trigonometrijskim nivelmanom određene visine trigonometrijskih točaka. U ovom radu se želi
pokazati na temelju obavljenih kontrola kvalitete da li se model geoida prema unaprijed postavljenim
zahtjevima točnosti može koristiti za sva mjerila kartiranja.
2. METODOLOGIJA
Hrvatski geodetski institut već duže vrijeme u kontinuitetu obavlja kontrolu kvalitete geodetskih
proizvoda TK25 i Digitalne ortofoto karte mjerila 1:5000 i 1:2000 od različitih proizvoditelja za potrebe
Državne geodetske uprave.
Sl. 2.1. Postupak kontrole kvalitete
Za potrebe sustavne provedbe kontrole kvalitete sadržaja TK25, DOF-a 1:5000 i 1:2000, te
provjere apsolutne i relativne točnosti geodetske osnove i topografskog detalja sukladno trenutnoj
opremljenosti Instituta mjernim instrumentarijem, obavljaju se planiranja i izvedbe terenskih radova
primjenjujući sve geodetske metode izmjere prema zahtjevima
sustava kontrole kvalitete.
Dokumentacija na temelju koje se provodi postupak kontrole kvalitete u HGI-u je u potpunosti definirana
ISO standardima. Izvorni dokumenti koji su poslužili za izradu dokumentacije su sljedeće ISO norme:
ISO 19113 Geographic Information-Quality Principles, ISO 19114 Geographic Information - Quality
evaluation procedures, ISO 19115 Geographic Information – Metadata, ISO 2859 Sampling procedures
for inspection by attributes, ISO 3951 Sampling procedures and charts for inspection by variables for
percent nonconforming.
Elaborati određivanja orijentacijskih točaka i Elaborati aerotriangulacije u cjelini i pojedinim
dijelovima sadržavaju informacije i podatke koje je potrebno, ali ujedno i nemoguće, kontrolirati ukoliko
nisu dostupni polazni podaci koji su osnova za kontrolu točnosti u okviru postavljenih zahtjeva prema
Pravilniku o načinu topografske izmjere i o izradbi državnih zemljovida, specifikacijama proizvoda, ili
prema zahtjevima razvijenog sustava kontrole kvalitete proizašlog iz međunarodnih projekata
CRONOGIP I i CRONOGIP II. Tako se orijentacijske točke određuju s instrumentarijem koji osigurava
položajno i visinsko određivanje sa standardnim odstupanjem manjim od 1/4 predviđenog dopuštenog
odstupanja za njih. U postupku kontrole kvalitete izabire se, ukoliko to u specifikacijama proizvoda nije
drugačije definirano, između potpune ili uzorkovane metode. U potpunoj kontroli svi objekti određenog
tipa u skupu podataka moraju biti kontrolirani. Taj tip kontrole najviše je prikladan za automatiziranu
kontrolu implementirajući adekvatne softvere. Kako bi reducirali količinu posla, kontrolu je moguće obaviti
na uzorku a ta metoda je bazirana na općim internacionalnim standardima kojima se utvrđuju veličine
uzoraka a to su: ISO 2859 Sampling procedures for inspection by attributes, ISO 3951 Sampling
procedures and charts for inspection by variables for percent nonconforming. Nakon što je proizvod
podvrgnut kontroli kvalitete potrebno je odlučiti da li se skup podataka koji je kontroliran prihvaća kao
dobar, odbija kao loš, ili ga treba proširiti. Samo izvješće o provedenoj kontroli kvalitete trebalo bi
sadržavati sljedeće elemente: skup podataka koji je kontroliran, korišteni elementi kvalitete, dopuštena
odstupanja, potpuna ili uzorkovana metoda, korišteni hardver i softver, mjerenja i računanja, usporedbu
rezultata i odstupanja, te zaključak o prihvaćanju ili odbijanju proizvoda. Sustavna i dosljedna kontrola
kvalitete proizvoda koja se provodi u pojedinim organizacijskim jedinicama Hrvatskog geodetskog
instituta pretpostavlja vrlo dobru koordinaciju i uvažavanje međusobnih potreba između HGI-a i DGU-a.
3. REZULTATI
Za kontrolu DOF-a i DMR-a na području B1/C1, koji pokrivaju prostor od 52 lista DOF-a oko
Plaškog, u apsolutnom smislu obavljena su kontrolna nivelmanska mjerenja orijentacijskih točaka u
- 102 -
odnosu na najbliže repere na 5 različitih lokacija koje su bile definirane odabranim topografskim
detaljem. Kontrolna nivelmanska mjerenja orijentacijskih točaka za područje B1/C1, slika 3.1., obavljena
su prema normativima za tehnički nivelman, postranim nivelmanskim vlakovima, korištenjem
automatskog elektroničkog nivelira LEICA NA3003. Obrada podataka mjerenja i izjednačenje provedeno
je primjenom izjednačenja direktnih mjerenja i to tzv. dvostrukih mjerenja. Mjerenja su obavljena u dva
suprotna smjera od istog opažača, s istim instrumentom, uz slične vremenske prilike. Najvjerojatnija
vrijednost nepoznanice računana je kao (Feil, 1990):
X i = ( L1 + L2 ) / 2
(1)
Standardno odstupanje najvjerojatnije vrijednosti iz dvostrukih mjerenja dobiva se primjenom
zakona o prirastu pogrešaka na izraz (1):
sH =
1 d td
,
2 n
(2)
pri čemu je n broj dvostruko mjerenih veličina.
Dopuštene razlike pri dvostrukom mjerenju nivelmanskih strana u tehničkom nivelmanu iznose
prema Pravilniku o radovima geometrijskog nivelmana (Klak, Feil i Rožić, 1993):
d1 = ±8 s mm.
(3)
Deklarirana mjerna nesigurnost elektroničkog instrumenta LEICA NA3003 na 1 km dvostrukog
nivelmana je ±1.5 mm, odnosno ±0.7 mm s certificiranim kodiranim letvama. Kao medij za pohranu
mjernih podataka služio je REC-modul.
Prema Elaboratu određivanja orijentacijskih točaka normalne ortometrijske visine orijentacijskih
točaka računane su iz podataka undulacija geoida, pri čemu je korišten model geoida za područje
Republike Hrvatske HRG2000. Normalne ortometrijske visine orijentacijskih točaka iz kontrolnih mjerenja
odnose se na najbliže repere iz državne visinske mreže oslonjene na ishodišni reper u Trstu.
Legenda:
1
- orijentacijske tocke
2A
- koristeni reperi
0
1
2
3
km
4
5
3
4
35
5
35A
6
8
19740
34
8A
22420
9C
37
48
10
11
15
17
16
14
18
33
22425
19
30
31
32
Sl.3.1. Područje B1/C1
Na temelju tako određenih visina, uz pretpostavku primjerene točnosti određivanja položaja i
visina orijentacijskih točaka što je u potpunosti realizirano prema ispisu ocjene točnosti, moguće je
donijeti ocjenu uporabivosti primjene modela geoida u postupku računanja normalnih ortometrijskih
visina uz postavljene zahtjeve točnosti prema Pravilniku o načinu topografske izmjere i o izradbi državnih
zemljovida.
Tablica 3.1. Visinske razlike između repera i orijentacijskih točaka
19740
Visinska
razlika ∆h1
[m]
15.663
Visinska
razlika ∆h2
[m]
15.669
Razlika
∆h1-∆h2
[mm]
6
Dopuštena
razlika
[mm]
8
1.02
∆h
[m]
15.666
8
100.872
100.884
12
13
2.52
100.878
9C
22425
24.432
24.435
3
9
1.32
24.434
10
48
0.502
0.503
1
4
0.29
0.502
33
22420
22.909
22.918
9
9
1.36
22.913
Broj
OT
Od repera
5
6
- 103 -
Udaljenost
[km]
Na temelju izračunanih visina orijentacijskih točaka proizašlih iz kontrolnih mjerenja za utvrđenu
veličinu uzorka sukladno ISO standardu i visina orijentacijskih točaka preuzetih iz elaborata određivanja
orijentacijskih točaka za područje projektne zadaće izračunano je standardno odstupanje prema izrazu:
s=
ε2
∑n
,
(4)
pri čemu je:
s = standardno odstupanje; ε = odstupanje u pojedinoj točci; n = broj točaka u uzorku.
Računano
Standardno odstupanje po visini
0.1606
Broj korištenih točaka u uzorku
5
Ukupan broj točaka
26
Računana ISO veličina uzorka
5
Računani faktor za veličinu uzorka
1.54
Tablica 3.2. Razlika visina iz skupa podataka i kontrolnih mjerenja
Podaci iz skupa podataka
da
3
259.55
iz kontrolnih mjerenja
Visina (Z)
[m]
259.73
da
6
489.97
490.18
-0.206
0.042
da
2
404.03
404.20
-0.174
0.030
da
1
363.72
363.85
-0.132
0.017
da
5
621.04
621.12
-0.082
0.007
Valid
St. odst. [mm] Visina (Z) [m]
Razlike
DZ
[m]
-0.179
Kvadrat razlike
SQ(DiffZ)
0.032
4. ANALIZA
Za iskazivanje procjene da li je standardno odstupanje za odabranu veličinu uzorka, tablica 4.1.,
signifikantno veće od dopuštenog odstupanja koristi se statistička metoda zasnovana na normalnoj
razdiobi koja pretpostavlja da standardno odstupanje slijedi normalnu razdiobu.
Tablica 4.1. Statističke vrijednosti za testiranje standardnog odstupanja
Broj točaka u skupu podataka
Od
Do
26
50
51
90
91
150
151
280
281
400
401
500
501
1200
1201
3200
3201
10000
10001
35000
35001
150000
150001
500000
> 500000
Veličina uzorka
n
5
7
10
15
20
25
35
50
75
100
150
200
200
Standardno odstupanje iz uzorka:
Veličina skupa (uzorka):
Dopušteno odstupanje za standardno odstupanje:
Standardno odstupanje je preveliko ako je:
σ<
F
(F0.05,n-1,∞)
1.54
1.45
1.37
1.30
1.26
1.23
1.20
1.16
1.13
1.12
1.09
1.08
1.08
s=0.1606 m,
n=5,
σ=0.180 m,
s
, što u ovom konkretnom slučaju nije ispunjeno
F
budući je 0.180>0.1043.
Nijedna kontrolirana točka za potrebe kontrole DOF-a nije u rezultatima iskazala prisutnost grube
pogreške (trostruko standardno odstupanje). Ocjena točnosti obavljenih kontrolnih nivelmanskih
mjerenja, tablica 3.2., upućuje na primjerenu preciznost koja je postignuta pri mjerenjima i može poslužiti
za procjenu kvalitete određivanja orijentacijskih točaka u apsolutnom smislu u okviru postavljenih
zahtjeva točnosti. Položajni opisi orijentacijskih točaka moraju jednoznačno i precizno definirati
topografski detalj, te na taj način omogućiti neovisno ponavljanje radova, odnosno obavljanje kontrolnih
mjerenja i na temelju njih donošenja pouzdanih zaključaka o kvaliteti određivanja orijentacijskih točaka,
- 104 -
što se u konkretnom slučaju na orijentacijskoj točci broj 5 pokazalo kao evidentan nedostatak. U svim
dosada izrađenim elaboratima kao zajednička karakteristika pokazalo se nedovoljno dobro definiranje
orijentacijske točke pa su i za ove točke koje su bile predmet kontrole moguće pogreške u visini pri
identifikaciji do 2 cm, što ne mijenja bitno rezultate i zaključke koji su iz njih proizašli.
5. ZAKLJUČAK
Obzirom na «Pravilnik o načinu topografske izmjere i o izradbi državnih zemljovida» po kojem
maksimalna standardna odstupanja određivanja položaja orijentacijskih točaka za mjerilo kartiranja 1:
5000 iznose položajno 12 cm, a visinski 18 cm, može se reći da razlike visina na orijentacijskim točkama
zadovoljavaju uvjete iz Pravilnika. Na temelju rezultata kontrolnih nivelmanskih mjerenja na
orijentacijskim točkama, gdje je ostvarena primjerena točnost određivanja visina orijentacijskih točaka,
proizlazi da je primjena modela geoida u postupku računanja normalnih ortometrijskih visina uz
postavljene zahtjeve točnosti moguća za mjerilo kartiranja 1:5000 i sitnija, dok bi se za krupnija mjerila
kartiranja, na temelju provedene kontrole, trebalo izvršiti povezivanje na repere državne visinske mreže.
LITERATURA
Feil, L. (1990): Teorija pogrešaka i račun izjednačenja - drugi dio, Geodetski fakultet Sveučilišta u
Zagrebu.
Geodis (2004): Elaborat određivanja orijentacijskih točaka, Elaborat aerotriangulacije i DMR-a – zadaća:
CARDS I – blok B1/C1, Zagreb.
Klak, S, Feil, L., Rožić, N. (1993): Pravilnik o radovima geometrijskog nivelmana, Prijedlog, Zagreb.
Narodne novine (1999): Pravilnik o načinu topografske izmjere i o izradbi državnih zemljovida, Zagreb.
- 105 -
- 106 -
KONTROLA KVALITETE DOF-A U PROCESU KATASTARSKE IZMJERE*
Slavko Lemajić, Višnja Miloš, Ilija Grgić
SAŽETAK
Hrvatski geodetski institut je započeo sa stručnim aktivnostima 1.12.2001. godine. U početnom
razdoblju Institut je obavljao poslove kontrole kvalitete topografskih karata u mjerilu 1:25000 i digitalnih
ortofoto karata u mjerilu 1:5000. Tijekom vremena preuzeo je i druge zadaće sukladno Programu
državne izmjere i katastra nekretnina za razdoblje 2001.-2005. godine (Hrvatski Sabor, 2001). Krajem
2003. godine potpisan je Ugovor između Državne geodetske uprave i Hrvatskog geodetskog instituta za
pružanje tehničkih usluga kontrole kvalitete digitalnih ortofoto planova u mjerilu 1:2000 u svrhu
uspostave katastra nekretnina i obnove zemljišnih knjiga koji se financira iz zajma Svjetske banke.
Institut je u dosadašnjem periodu obavljao kontrolu kvalitete za ukupno 14 katastarskih općina. Kontrola
kvalitete za svaku pojedinu katastrasku općinu obavlja se po fazama. U radu je prikazan proces kontrole
kvalitete s opisom pojedinih faza kontrole kvalitete.
KLJUČNE RIJEČI
kontrola kvalitete, plan leta, zračni snimci, skenirani snimci, aerotriangulacija,
digitalni model reljefa, digitalni ortofoto
ABSTRACT
Croatian Geodetic Institute started with professional activties at 1.12.2001. At the beginning
period of time Institute has performed quality controls of Topographic maps in scale 1:25000 and digital
orthophotos in scale 1:5000. During the time CGI has undertaken and other tasks according to Program
for state survey and cadastre 2001.-2005. (Croatian Parliament, 2001). At the end of 2003 was signed
the contract between SGA and CGI for tehnical support of quality control of digital orthophotos in scale
1:2000 for establishment of cadastre and real estate which is financed by World Bank. Instittute was
done quality control for 14 cadastral municipality. Quality control is done step by step. In paper is shown
process of quality control with description of single phase of quality control.
KEYWORDS: quality control, flight plan, aerial photos, scanned photos, aerial triangulation, digital
terrain model, digital ortophoto
1. UVOD
Hrvatski geodetski institut je započeo s obavljanjem stručnih poslova 1.12.2001. godine. U
početnom periodu, Institut je uglavnom obavljao pregled topografskih karata u mjerilu 1:25000 te
digitalnih ortofoto karata u mjerilu 1:5000. Tijekom vremena započet je proces kontrole ostalih proizvoda
i potproizvoda nastalih kao rezultat proizvodnje unutar privatnih geodetskih tvrtki. Svi poslovi kontrole
kvalitete obavljeni su za potrebe DGU (Sektor za topografsku izmjeru i državne zemljovide) u okviru
realizacije Programa državne izmjere i katastra nekretnina za razdoblje 2001.-2005. godine (Hrvatski
sabor, 2001). U drugoj polovici 2004. godine kao rezultat hrvatsko-norveškog geoinformacijskog projekta
(CRONO-GIP) razvijen je sustav kontrole kvalitete zasnovan na ISO normama (PMM, 2003). U prosincu
2003. godine potpisan je s Državnom geodetskom upravom Ugovor za pružanje Tehničkih usluga
kontrole kvalitete digitalnih orotofoto karata u mjerilu 1:2000 u okviru katastarskih izmjera u svrhu
uspostave katastra nekretnina i obnove zemljišne knjige u okviru Projekta sređivanja zemljišnih knjiga i
katastra.
2. SPECIFIKACIJA I REALIZACIJA POSLOVA
Predmet obavljanja poslova kontrole kvalitete jesu digitalni ortofoto planovi u mjerilu 1:2000.
Osim kontrole kavlitete konačnog proizvoda, obuhvaćene su i kontrole kvalitete važnijih faza iz
proizvodnog procesa izrade DOF-a.
*
Zagrebu 7.-9.3.2005. godine. Objavljeno u Zborniku radova Kongresa (Lemajić, S., Miloš, V., Grgić, I.:
Kontrola kvalitete DOF-a u procesu katastarske izmjere. Zbornik radova, Treći hrvatski kongres o
katastru s međunarodnim sudjelovanjem, Hrvatsko geodetsko društvo, Zagreb, 2005, 327-335).
- 107 -
Osnova i temeljna načela primarno su određena sukladno odredbama Ugovora, Tehničkim
specifikacijama o izradi DOF-a, standardima i pravilima struke te posebnim naputcima izdanim od DGU.
Dopunska osnova za obavljanje kontrole kvalitete sadržana je u pozitivnim zakonima i važećim
propisima u Republici Hrvatskoj te raspoloživim izvornicima: Zakon o državnoj izmjeri i katastru
nekretnina (Hrvatski Sabor, 1999), Uredba o snimanju iz zraka (Vlada RH, 2003), Pravilnik o načinu
topografske izmjere i o izradbi državnih zemljovida (DGU, 2001, u daljnjem tekstu Pravilnik), Uputa za
izradu digitalnih ortofoto karata u mjerilu 1:5000-DOF (PMM, 2003), Pravilnik o načinu čuvanja i
korištenja dokumentacije i podataka državne izmjere i katastra nekretnina (DGU, 2001).
Sadržajem poslova kontrole kvalitete definirani su elementi kvalitete, izvornici na temelju kojih će se
kontrola obaviti te metoda pregleda.
Elementi kvalitete za koje se pregled obavlja metodom uzorkovanja, izbor veličine uzorka obavlja
se sukladno tablici 1 i dokumenta Guidelines for Sampling (PMM, 2004).
Tablica 1. Određivanje veličine uzorka
Za kontrole metodom uzorkovanja temeljene na
pogreškama nedostajanja objekata
Broj
objekata
Po (%) =
Veličina
od
do
uzorka
1
8
Svi objekti
9
50
8
51
90
13
91
150
20
151
280
32
281
400
50
401
500
60
Po – dopušteno odstupanje
1.
0
2.
0
3.
0
5.
0
1
1
1
2
2
3
3
1
1
2
2
3
3
4
1
1
2
3
3
4
5
1
1
3
4
4
6
7
Za kontrole metodom uzorkovanja
osnovane na kontrolama
standardnog odstupanja
Broj
objekata
FVeličina
razdio
uzorka
ba
Od
Do
1
26
Svi objekti
1
26
50
5
1.54
51
90
7
1.45
91
150
10
1.37
151
280
15
1.30
281
400
20
1.26
401
500
25
1.23
Poslovi kontrole kvalitete obavljaju su u četiri faze. Prva faza sadrži kontrolu kvalitete projekta
aerofotogrametrijskog snimanja i rasporeda orijentacijskih točaka, druga faza sadrži kontrolu izvedenog
snimanja, treća faza sadrži kontrolu aerotriangulacije bloka, dok se kontrola kvalitete digitalnog modela
reljefa i digitalnih ortofoto planova obavlja u četvrtoj fazi. Svaka naredna faza obavljanja radova zahtijeva
zadovoljenje kontrole kvalitete u prethodnoj fazi. Institut je do kraja 2004. godine obavljao kontrole
kvalitete proizvoda za 14 katastarskih općina u različitim fazama.
Posao kontrole kvalitete DMR-a i DOF-a je obavljan u četiri faze:
- kontrola kvalitete projekta aerofotogrametrijskog snimanja i rasporeda orijentacijskih točaka,
- kontrola kvalitete fotosignalizacije orijentacijskih točaka, prikaza ostvarenog leta, izrade
fotomaterijala te izrade digitalnog zapisa snimaka ili skeniranja,
- kontrola kvalitete aerotriangulacije,
- kontrola kvalitete digitalnog modela reljefa i digitalnih ortofoto planova u mjerilu 1:2000.
2.1. KONTROLA KVALITETE PROJEKTA AEROFOTOGRAMETRIJSKOG SNIMANJA I
RASPOREDA ORIJENTACIJSKIH TOČAKA
Elementi kvalitete koji su obuhvaćeni kontrolom kvalitete prikazani su u tablici 2. Plan leta s
rasporedom orijentacijskih točaka isporučuje se u analognom i digitalnom obliku. Na planu leta mora biti
označeno područje snimanja (područje katastarske općine). Planirane razlike mjerila uslijed visinskih
razlika terena ne smiju biti veće od 15 % (DGU, 2001).
Tablica 2. Kontrola kvalitete projekta aerofotogrametrijskog snimanja i
rasporeda orijentacijskih točaka
Kontrola
Traženi izvornik
ili kontrolna
vrijednost
Izvornik za obavljanje
pregleda
Mjesto
pregleda
Način
pregleda
Isporuka
Plan leta
Pravilnik
Tehničke specifikacije
ured
Manualni
kompletni
Pokrivenost
područja
snimanja
Područje zadatka
ured
Manualni
kompletni
Mjerilo snimanja
1:5000 za
izgrađena
područja, 1:8000
za ostala
područja
ured
Manualni
kompletni
- 108 -
Preklop
Fokusna duljina
kamere
Raspored
orijentacijskih
točaka
30% poprečni
60% uzdužni
153 mm
Signalizirane
točke geodetske
osnove
Pravilnik
Pravilnik
Pravilnik
ured
ured
ured
Manualni
kompletni
Manualni
kompletni
Manualni
kompletni
Izvješće o obavljenoj kontroli kvalitete projekta snimanja s nalazima dostavlja se na daljnje
postupanje u DGU uz ocjenu da li je projekt prihvatljiv ili nije. U slučaju da je kontrolom kvalitete
ustanovljeno da plan leta nije prihvatljiv, izvoditelj korigira postojeći plan ili izrađuje novi plan te ga
dostavlja na ponovni pregled.
2.2. KONTROLA KVALITETE FOTOSIGNALIZACIJE ORIJENTACIJSKIH TOČAKA, PRIKAZA
OSTVARENOG LETA, IZRADE FOTOMATERIJALA TE IZRADE DIGITALNOG ZAPISA
SNIMAKA ILI SKENIRANJA
Druga faza kontrole kvalitete (tablica 3) obuhvaća kontrolu kvalitete fotosignalizacije
orijentacijskih točaka, prikaza ostvarenog leta, izrade fotomaterijala te izrade digitalnog zapisa snimaka
(skeniranje).
Kontrola kvalitete fotosignalizacije obavlja se terenskom provjerom na odabranom uzorku
sukladno tablici 1. Na kontaktnim kopijama obavlja se provjera kvalitete preslikanosti i vidljivosti
signaliziranih točaka. U Elaboratu fotosignalizacije treba biti razvidno prikazano koje točke su planirane
planom snimanja, koje su zamjenske točke te koje točke su se preslikale na kontaktnim kopijama. Na
kontaktim kopijama se provjerava numeracija točaka koja na planu orijentacijskih točaka i skici
izvedenog snimanja treba biti jedinstvena.
Uzdužni preklop kontrolira se za svaki niz mjerenjem baza na snimcima izabranih modela.
Modeli se za svaki niz biraju metodom uzorkovanja (tablica 1). Kontrolom kvalitete utvrđuje se
maksimalni i prosječni preklop u svakom nizu. Poprečni preklop se mjeri na odabranim mjestima te se
utvrđuje da li postoje stereoskopske praznine.
Ostvarene visine leta se za svaki niz očitaju sa snimaka i uspoređuju sa projektiranim visinama
leta te su izračunaju odstupanja u postocima. Kontrola položajnog odstupanja izvedenih osi nizova od
planiranih određuje se nanošenjem središta snimaka na kopiju topografske karte na kojoj je izrađen plan
leta.
Tablica 3. Kontrola kvalitete fotosignalizacije orijentacijskih točaka, prikaza ostvarenog leta,
izrade fotomaterijala te izrade digitalnog zapisa snimaka ili skeniranja
Kontrola
Isporuka
Traženi izvornik
ili kontrolna
vrijednost
Položajni opisi,
skica izvedenog
snimanja,
kalibracija
kamere, film,
kontaktne kopije
pregleda
Mjesto
pregleda
Način
pregleda
ured
Manualni
kompletni
teren
Manualni
uzorkovani
teren
Manualni
uzorkovani
Izvedena
signalizacija
Izvedena
signalizacija
Načina
signalizacije
Pokrivenost
područja
snimanja
Dimenzija signala
90x30cm
Projekt
aerofotogrametrijskog
snimanja
Pravilnik
Područje zadatka
ured
Manualni
kompletni
ured
Manualni
kompletni
ured
ured
Pravilnik
ured
Manualni
kompletni
ured
Manualni
kompletni
Izvedeno mjerilo
snimanja
Izvedeni
preklopa
Fokusna duljina
kamere
Odstupanja
projekcionih
centara
Kalibracija
kamere
1:5000 izgrađena
područja, 1:8000
ostala područja
30% poprečni
60% uzdužni
153 mm
Planirani položaji
projekcionih
centara
Kalibracija
kamere izvršena
ne kasnije od
dvije godine
- 109 -
Manualni
kompletni
Manualni
kompletni
Vrsta filma
Kvaliteta filma
Stereoprekrivanje
Kvaliteta
snimanja
Format digitalnog
zapisa
Čitljivost
digitalnog zapisa
Kvaliteta
skeniranja
AGFA COLOR H
100
Film
(denzitometrijska
mjerenja,
oštećenja,
kompletnost
informacija)
Potpuno
stereoprekrivanje
Prisutnost oblaka,
magle, sjena,
vegetacije i
snijega
«tiff», rezolucija
28µm
ured
Manualni
uzorkovani
Pravilnik
ured
Manualni
uzorkovani
Pravilnik
ured
Manualni
Uzorkovani
Pravilnik
ured
Manualni
Uzorkovani
ured
Čitljivost datoteka
ured
Histogram
Specifikacija proizvoda
skenirani snimci
ured
Manualni
Uzorkovani
Manualni
Uzorkovani
Manualni
Uzorkovani
Kontrolom kvalitete fotomaterijala obuhvaćeni su film i kontaktne kopije. Pregledom se ispituje
kvaliteta filma tj. da li postoje oštećenja filma uzrokovana razvijanjem ili premotavanjem. Također se
obavlja pregled ispravnosti negativa koja se određuje denzitometrijskim mjerenjem (DGU, 2001). Na
kontaktnim kopijama provjerava se prisutnost oblaka i dubokih sjena te kvaliteta preslikavanja i
korektnost označavanja fotosignala.
Skenirani snimci trebaju biti isporučeni po nizovima snimanja. Svi digitalni zapisi moraju biti
čitljivi. Veličina slikovnog elementa mora biti 28µm ili bolja sukladno Tehničkim specifikacijama.
Eventualna oštećenja koja su bila uočena na filmu trebaju biti uklonjena postupkom retuširanja u procesu
obrade skeniranih snimaka. Za svaki snimak u digitalnom zapisu koji je predmet kontrole kvalitete
obavlja se kontrola kvalitete krivulje histograma. Za skenirane snimke u boji postoje tri krivulje
histograma, tj. za svaku boju iz RGB spektra boja (crvena, zelena i plava). Izgled krivulja za svaku boju
mora biti sličan (PMM, 2003), tj. svaka krivulja mora biti u približno istom rasponu tonova (10-250).
2.3. KONTROLA KVALITETE AEROTRIANGULACIJE
Kontrola ispravnosti i točnosti izjednačenja bloka aerotriangulacije obavlja se sukladno članku
14. i članku 15. Pravilnika i obuhvaća elemente navedene u tablici 4.
Pri kontroli kvalitete treba voditi računa kojom metodom su određene vezne točke budući da se
metoda automatskog određivanja veznih točaka može primjenjivati isključivo na ravničastim područjima
bez vegetacije s jednostavnom teksturom koja se ne ponavlja. Povećanjem rezolucije ne postiže se
proporcionalno povećanje točnosti (Geodetski fakultet, 2003).
Osim navedenog, potrebno je obratiti pažnju na pravilan raspored i odgovarajuću točnost
osnovnih zadanih točaka bloka, ispravnost ulaznog podatka za visinu osnovnih zadanih točaka bloka
(promjena visine za visinu stabilizacije), valjanost kalibracije ili kontrole kalibracije stereoinstrumenta,
odnosno pri korištenju digitalnih fotogrametrijskih sustava važna je valjanost kalibracije i kontrola
kalibracije skenera, kvaliteta unutarnje orijentacije, postavljanje ispravnih parametara u računanju
aerotriangulacije, te analiza dobivenih rezultata.
Tablica 4. Kontrola kvalitete aerotriangulacije
Kontrola
Traženi izvornik
ili kontrolna
vrijednost
pregleda
Mjesto
pregleda
Način
pregleda
Isporuka
Elaborat AT
Pravilnik
ured
Manualni
kompletni
Pravilnik
ured
Manualni
kompletni
Pravilnik
ured
Manualni
kompletni
ured
Manualni
kompletni
Sadržaj
Elaborata
Raspored OT
Točnost
aerotriangulacije
Sadržaj
Elaborata
(Tehničko
izvješće,
pregledna skica,
mjerenje,
izjednačenje itd)
Pravilan
raspored OT
Max. Srednja
pogreška
izjednačenja
bloka M=±0.10m
- 110 -
Kompletnost
Unutarnja
orijentacija
Elementi vanjske
orijentacije,
Izjednačene
koordinate
Unutarnja
orijentacija i br.
korištenih rubnih
markica (min. 4)
Pravilnik
ured
Manualni
kompletni
Pravilnik
ured
Manualni
uzorkovani
Proces kontrole kvalitete koju trenutno provodi Institut obavlja se isključivo kontrolom
dostavljenih Elaborata aerotriangulacije, slijedeći elemente kvalitete navedene u tablici 4.
Kontrolom kvalitete Elaborata aerotriangulacije uglavnom se uočavaju sljedeći nedostaci:
nepotpunost isporuke tj. nedostatak ključnih dijelova Elaborata aerotriangulacije,
dimenzije signala u neskladu s dimenzijama signala zadanim u Tehničkim specifikacijama, što
dovodi do pogrešaka u izmjeri,
visine osnovnih zadanih točaka bloka nekorigirane za visinu stabilizacije,
pri korištenju digitalnih fotogrametrijskih sustava nepoštivanje pravila o kontroli kalibracije
skenera, budući se različitim parametrima skeniranja dobiju različiti podaci koji su polazište za daljnji rad.
Pri velikim promjenama parametara skeniranja može doći do nesuglasja zadataka izvedenih s različitim
parametrima skeniranja,
opažanje točaka koje se nalaze bliže od 10 mm od ruba snimka što nije ispravno zbog pada
kvalitete snimke i moguće promjene dimenzije emulzije,
ocjena točnosti «a priori» zadanih koordinata ne odgovara ocjeni točnosti dobivenoj u
određivanju orijentacijskih točaka,
kriteriji za prekid iteracija računanja bloka zadani s nerealnim veličinama.
2.4. Kontrola kvalitete DMR-a i DOF-a
Nakon obavljanja kontrole kvalitete aerotriangulacije i prihvaćanja rezultata računanja i kontrole
aerotriangulacije pristupa se četvrtoj i posljednjoj fazi kontrole kvalitete (tablica 5).
Uz ispunjavanje uvjeta isporuke (izvješće, digitalni zapis DMR-a i DOF-a) pristupa se kontroli
kvalitete digitalnog zapisa (format zapisa i čitljivost datoteka). Podaci DMR-a trebaju sadržavati
prijelomnice, strukturne linije (linije oblika), pojedinačne markantne točke te raster visinskih točaka na
pravilnom razmaku.
Kontrola kvalitete podataka DMR-a obavlja se vizualnom provjerom izračunatog modela (sjene)
pomoću kojeg je moguće otkrivanje grubih pogrešaka. Također, provjera grubih pogrešaka obavlja se i
streoskopskim promatranjem izabranih modela.
Tablica 5. Kontrola kvalitete DMR-a i DOF-a
Kontrola
Isporuke
Format
digitalnog
zapisa DMR-a
Čitljivost
digitalnog
zapisa DMR-a
Struktura
podataka
Točnost DMR-a
DOF
Traženi izvornik
ili kontrolna
vrijednost
Izvješće, digitalni
zapis DMR-a,
digitalni zapis
DOF-a
pregleda
Mjesto
pregleda
Način
pregleda
Pravilnik o
ured
Manualni
kompletni
Format zapisa
DXF
ured
Manualni
kompletni
Čitljivost datoteke
ured
Manualni
kompletni
Pravilnik
ured
Automatski
kompletni
teren
Manualni
uzorkovani
ured
Manualni
kompletni
Prijelomnice,
strukturne linije,
karakteristične
točke, točke grida
m=±0.20m za
izgrađeno
područje
m=±0.50m za
ostalo područje
Format zapisa,
rezolucija,
čitljivost zapisa,
histogram,
dimenzije DOF-a,
veze listova
- 111 -
Kartografski
sadržaj
Točnost DOF-a
Format zapisa,
vanjski opis
(službena podjela
detaljnih listova
kat. plana
1:2000)
m=±0.20m za
izgrađeno
područje,
m=±0.50m za
ostalo područje
ured
Manualni
kompletni
teren
Manualni
uzorkovani
Točnost DMR i njegova kvaliteta direktno je povezana i reflektira se pri izradi DOF-a. Mjerene
vrijednosti točaka profila (prave vrijednosti) uspoređuju se s interpoliranim visinama podataka DMR-a te
se računaju standardna odstupanja. Sukladno Tehničkim specifikacijama tražena točnost DMR-a mora
biti ±0.20m za izgrađeno područje i ±0.50m za ostala područja.
Kontrolom kvalitete DOF-a obuhvaćene su provjere formata i čitljivosti digitalnog zapisa, veličina
slikovnog elementa (0.20m) te dimenzije lista (7500x5000 slikovnih elemenata). Svi listovi moraju biti
tonski izjednačeni bez vidljivih prijelaza pri izradbi mozaika. Krivulja histograma za svaki list DOF-a mora
biti ujednačena. Također, na spojevima listova DOF-a ne smije postojati tonska razlika uslijed
eventualnog tonskog izjednačenja svakog pojedinog lista.
Kartografski sadržaj za svaki list sastoji se od vanjskog opisa i okvira sukladno službenoj podjeli
na detaljne listove. Svi elementi moraju biti sadržani u jednom sloju i isporučeni u DWG digitalnom
zapisu.
3. ZAKLJUČAK
Tijekom 2004. godine Institut je obavljao kontrole kvalitete potproizvoda i proizvoda u procesu
katastarskih izmjera sukladno Ugovoru za pružanje tehničkih usluga kontrole kvalitete. Budući da su
definirani rezultati rada, navedeni u Tehničkim specifikacijama, Institut je proces kontrole kvalitete
razložio na četiri faze. Takav pristup u sustavu kontrole kvalitete pokazao se opravdanim jer je osigurao
kvalitetno praćenje procesa proizvodnje DMR-a i DOF-a kao ciljanog proizvoda. Poznavajući traženu
vrijednost, tj. zahtjevanu točnost potproizvoda i konačnih proizvoda, ovakvim pristupom osigurani su
traženi uvjeti. Također, evidentiranjem i otklanjanjem nedostataka u ranoj fazi proizvodnog procesa
postignuta je veća sigurnost da su konačni proizvodi sukladni normativno tehničkoj osnovi.
Izradom ili uvođenjem odgovarajućih specifikacija za proizvode DMR i DOF, koji se izrađuju iz
zračnih snimaka mjerila 1:5000 i 1:8000 i detaljno definiraju proizvodni proces, proizvod te dopuštena
odstupanja zasigurno mogu homogenizirati i ujednačiti dosadašnji različiti pristup pri izradbi digitalnog
ortofota u procesu katastarskih izmjera.
LITERATURA
Hrvatski sabor, 1999: Zakon o državnoj izmjeri i katastru nekretnina, Narodne novine br. 128/99, Zagreb
Hrvatski sabor, 2001: Program državne izmjere i katastra nekretnina za razdoblje 2001-2005, Narodne
novine br. 64/2001, Zagreb
DGU, 2001.: Pravilnik o načinu topografske izmjere i o izradbi državnih zemljovida, Narodne novine
55/01, Zagreb
DGU, 2001.: Pravilnik o načinu čuvanja i korištenja dokumentacije i podataka državne izmjere i katastra
nekretnina, Narodne novine 55/01, Zagreb
Vlada RH, 2003.: Uredba o snimanju iz zraka, Narodne novine 116/03, Zagreb
PMM, 2003.: Uputa za izradu digitalnih ortofoto karata u mjerilu 1:5000 (DOF), DGU, Zagreb
PMM, 2003.: Specifikacija proizvoda DMR, DGU, Zagreb.
PMM, 2003.: Specifikacija proizvoda zračni snimci i orijentacijske točke, DGU, Zagreb
PMM, 2003.: Specifikacija proizvoda skenirani snimci, DGU, Zagreb
PMM, 2003.: Specifikacija proizvoda aerotriangulacija, DGU, Zagreb
PMM, 2004.: Guidelines for Sampling, HGI, Zagreb
Geodetski fakultet, 2003.: Studija o aerotriangulaciji, DGU, Zagreb
- 112 -
METODOLOGIJA ODREĐIVANJA CRTE SREDNJIH VIŠIH VISOKIH VODA*
Bojan Barišić, Ivica Vilibić, Ilija Grgić
SAŽETAK
Crta srednjih viših visokih voda (SVVV) određuje granicu unutar pomorskog dobra između
morske obale i ostalog dijela pomorskog dobra. Razradom pravne regulative vezane uz pomorsko dobro
javlja se potreba da se crta SVVV kvalitetno i jednostavno odredi. Pošto je crta SVVV usko vezana uz
mareografska mjerenja, za shvaćanje njene definicije potrebno se upoznati s rezultatima tih mjerenja.
Praktično određivanje crte SVVV svodi se na prijenos visina različitim nivelmanskim metodama pri čemu
je neophodno korištenje točaka visinskog sustava. Pošto se trenutno nalazimo u prelaznom razdoblju u
kojem je potrebno dosadašnju upotrebu povijesnog referentnog visinskog sustava zamijeniti novim
referentnim visinskim sustavom, više pažnje bit će posvećeno tome što nam te promjene donose.
KLJUČNE RIJEČI
pomorsko dobro, morska obala, mareografska mjerenja, srednje više visoke
vode, hrvatski visinski referentni sustav – HVRS71
ABSTRACT
Border between seacoast and remain parts of maritime domain is defined by the mean higher
high water (MHHW) line. Improvements in related lows are requesting well and easy practical definition
of the MHHW line. Tide gauge measurements are unavoidable in explanations of the MHHW line.
Different levelling methods are used to link national vertical reference frame benchmarks with aim to
practically define MHHW line. This is the time when Croatia is changing old vertical reference system to
new one and impact on the MHHW line determination is described.
KEYWORDS
maritime domain, seacoast, tide gauge measurements, mean higher high water, Croatian
vertical reference system – HVRS71
1. UVOD
Posljednjih godina sve se više počinje prepoznavati prirodna i gospodarska vrijednost našeg
obalnog područja te porast interesa za njegovim iskorištavanjem, kako od strane domaćih tako i
inozemnih poduzetnika. Želja da se naš obalni pojas što bolje zaštiti od stihijskog razvoja i devastacije,
kojima je bio izložen nekoliko posljednjih desetljeća, urodila je izradom nove te razradom već postojeće
zakonske regulative. Njom se, osim zaštite ovog osjetljivog dijela našeg teritorija, omogućava i
iskorištavanje njegove već davno prepoznate gospodarske vrijednosti.
Granicu pomorskog dobra s morske strane predstavlja vanjska granica teritorijalnog mora
Republike Hrvatske. Ona pak predstavlja morski pojas širok 12 morskih milja, računajući od polazne crte
u smjeru gospodarskog pojasa. Granica pomorskog dobra s kopnene strane određena je njenom
obalnom komponentom (Roić i Racetin, 2003).
Poseban dio našeg obalnog područja je morska obala koja spada u jedan od dijelova kopna koji
zajedno s unutarnjim morskim vodama, teritorijalnim morem, njihovim dnom i podzemljem, te u moru i
morskom podzemlju živim i neživim prirodnim bogatstvima čine pomorsko dobro. Morska obala proteže
se od crte srednjih viših visokih voda mora i obuhvaća pojas kopna koji je ograničen crtom do koje dopiru
najveći valovi za vrijeme nevremena, kao i onaj dio kopna koji po svojoj prirodi ili namjeni služi korištenju
mora za pomorski promet i morski ribolov, te za druge svrhe koje su u vezi s korištenjem mora, a koji je
širok najmanje šest metara od crte koja je vodoravno udaljena od crte srednjih viših visokih voda
(«Narodne novine», br. 158/03).
Za svaku županiju na čijem području postoji pomorsko dobro osniva se županijsko povjerenstvo
za granice pomorskog dobra. Povjerenstvo izrađuje prijedlog granice pomorskog dobra temeljem
godišnjeg plana upravljanja pomorskim dobrom ili iznimno temeljem zahtjeva. Zahtjev za utvrđivanje
granice pomorskog dobra podnosi se Povjerenstvu. Podnositelj zahtjeva za utvrđivanje granice
Zagrebu 7.-9.3.2005. godine. Objavljeno u Zborniku radova Kongresa (Barišić, B., Vilibić, I., Grgić, I.:
Metodologija određivanja crte srednjih viših visokih voda. Zbornik radova, Treći hrvatski kongres o
katastru s međunarodnim sudjelovanjem, Hrvatsko geodetsko društvo, Zagreb, 2005, 351-358).
*
- 113 -
pomorskog dobra može biti Vlada Republike Hrvatske putem Ministarstva mora, turizma, prometa i
razvitka, tijela državne uprave, tijela jedinice lokalne samouprave i fizičke i/ili pravne osobe. Jedan od
priloga u tom zahtjevu je i geodetski snimak područja ili ortofoto plan s uklopljenom kopijom katastarskog
plana, koji se izrađuje u skladu s propisima o topografskoj izmjeri i obavezno sadrži liniju koja predstavlja
crtu SVVV i liniju koja je šest metara udaljena od te crte («Narodne novine», br. 8/04).
Prema Zakonu o pomorskom dobru i morskim lukama crtu SVVV utvrđuje Hrvatski hidrografski institut
(HHI). Praktično HHI određuje razliku između geodetske nule i razine SVVV za određeno područje ili
prosjek za cijelu obalu, dok geodetska tvrtka, koja izrađuje geodetski snimak područja ili ortofoto plan,
pomoću te razlike utvrđuje granicu između morske obale i ostatka pomorskog dobra.
Spomenuta granica dijelom definira česticu pomorskog dobra na morskoj obali tj. određuje njenu
granicu prema moru. Njena važnost prema sadašnjim propisima velika je i u slučajevima kada se pojas
morske obale određuje na šest metara od crte SVVV. Bez obzira na buduće promjene zakonske
regulative, granica između morske obale i ostalog dijela pomorskog dobra (crta SVVV) ima veliki značaj
pri evidenciji i obilježavanju pojasa pomorskog dobra, pogotovo kada se uzme podatak da je duljina naše
obale 5835 km.
Kad se radi o određivanju visine neke točke potrebno se osloniti na točke službenog visinskog
sustava (repere). Uvođenjem novog visinskog referentnog sustava - HVRS71, dolazi do određenih
promjena u odnosu geodetske nule i razine SVVV, budući da je stari visinski referentni sustav po svojoj
definiciji prilično različit od novog.
Pošto su u službenoj upotrebi još uvijek oba visinska sustava treba vidjeti što nam primjena
visina repera iz određenog sustava donosi. U područjima gdje je potrebna veća točnost određivanja crte
SVVV, a posebno u područjima gdje je mali pad morske obale pa krivo određena visina znači pomak od
nekoliko metara u horizontalnom smislu, posebnu pozornost treba posvetiti točnosti visina. Kvaliteta
visinskog sustava vezana je uz točnost visine njegove okosnice. Nehomogenosti u točnosti starog
sustava izravno dovode do nehomogenosti u točnostima pri određivanju crte SVVV.
2. MAREOGRAFSKA MJERENJA
Dugoperiodičke oscilacije razine mora (podrazumijevaju se periodi veći od cca 1 min) najvećim
su svojim dijelom uzrokovane djelovanjem plimotvorne sile kao i djelovanjem atmosferskih sila, u prvom
redu djelovanjem tlaka zraka i vjetra. Plimotvorna sila je uzrokovana gravitacijskim privlačenjem vodenih
masa od strane Sunca i Mjeseca. Njezino djelovanje ima periodički karakter, sa najjače izraženim
poludnevnim i dnevnim komponentama. Djelovanjem plimotvorne sile morska razina periodički oscilira, a
epizode rasta odnosno pada razine mora definiramo kao morske dobi. Plima se definira kao vrijeme
rasta razine mora, dok oseka predstavlja vrijeme opadanja razine mora. Utjecaj plimotvorne sile može
mijenjati razinu mora preko deset metara u svjetskim oceanima, a u Jadranskom moru kao
poluzatvorenom bazenu od tridesetak centimetara u južnom Jadranu do jedan metar u sjevernom
Jadranu. Obzirom na konstelaciju Mjeseca i Sunca plimne oscilacije u Jadranskom moru su mješovitog
tipa, što znači da u pojedinim periodima dominiraju poludnevne komponente dvaput izmjenjujući morske
dobi u jednom danu (slika 1), dok u pojedinim periodima prevladavajući utjecaj imaju dnevne
komponente uzrokujući jednu plimu i oseku dnevno.
Uređaji koji registriraju periodične oscilacije morske razine nazivaju se mareografi, dok je izgled
tih oscilacija, kao rezultat mareografskih mjerenja, prikazan pomoću mareograma.
1.0
0.9
niže visoke vode
više visoke vode
razina mora [m]
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
pon.
više niske vode
uto.
niže niske vode
sri.
dan
cet.
pet.
Slika 1: Izgled mareograma kod poludnevnog tipa morskih mijena
- 114 -
Razina srednjih viših visokih voda dobije se kao aritmetička sredina, za određeni period (mjeseci,
godina), onih visokih voda koje su za poludnevni tip morskih mijena tijekom jednog dana više.
Srednja morska razina (SMR) je za geodeziju vrlo važan nivo i često služi za određivanje
visinskog datuma, a definira se kao aritmetička sredina satnih vrijednosti visina morske razine u nekom
periodu.
Važno je naglasiti da je mareografska mjerenja moguće povezati sa službenim visinskim
datumom preko repera koji se nalaze u blizini mareografa, te na taj način odrediti odnos između
geodetske nule i ostalih razina. Na taj način se može povezati i SMR na pojedinim postajama sa
službenim visinskim datumom te interpolirati za bilo koje područje na jadranskoj obali. Nakon toga se, za
izračun crte SVVV u odnosu na službeni visinski datum u cjelokupnom obalnom području Jadrana, može
koristiti više metoda:
(i)
izračunati razinu SVVV u odnosu na datum na pojedinim mareografskim postajama te načiniti
linearnu interpolaciju,
(ii)
izračunati razinu SVVV u odnosu na datum u svakoj točki uz obalu pomoću empirijski dobivenih
razdioba amplitude i faze pojedinih harmonijskih komponenti (npr. Polli, 1960), ili
(iii) izračunati razinu SVVV u odnosu na datum u svakoj točki pomoću vrijednosti amplitude i faze
pojedinih harmonijskih komponenti dobivenih numeričkim modelima.
3. REFERENTNI VISINSKI SUSTAVI U RH
Budući da se određivanje crte SVVV u slučaju kada znamo njen odnos prema geodetskoj nuli
(podatak HHI-a) svodi samo na iskolčenje visine, više ćemo pažnje posvetiti visinskom sustavu, jer se
trenutno nalazimo u prelaznom razdoblju u kojem je potrebno dosadašnju upotrebu povijesnog
referentnog visinskog sustava zamijeniti novim referentnim visinskim sustavom - HVRS71.
Povijesni geodetski visinski sustav, koji se još uvijek nalazi u službenoj upotrebi, ustrojen je za
vrijeme postojanja Austro-Ugarske monarhije. Njegov visinski datum vezan je uz vremensku epohu
1875. godine i određen je srednjom razinom mora na mareografu u Trstu iz jednogodišnjih mjerenja.
Drugu komponentu geodetskog visinskog sustava čini kao okosnica polje trajno stabiliziranih i do
izvedbe mjerenja I. nivelmana visoke točnosti (I. NVT; 1946-1953) očuvanih repera austrijskog preciznog
nivelmana (APN; 1874-1909), na koje su, uz zadržavanje njihovih izvornih nadmorskih visina, uklopljena
mjerenja I. NVT-a najjednostavnijim računskim postupcima i parcijalnim izjednačenjima (Feil i dr., 2003).
Državna geodetska uprava zadužena je da uvede nove službene geodetske datume i ravninske
kartografske projekcije u službenu uporabu, najkasnije do 1. siječnja 2010. godine. Novom visinskom
referentnom sustavu određuje se naziv – Hrvatski visinski referentni sustav za epohu 1971.5 – skraćeno
HVRS71. Ploha geoida koja je određena srednjom razinom mora na mareografima u Dubrovniku, Splitu,
Bakru, Rovinju i Kopru u epohi 1971.5 određuje se referentnom plohom za računanje visina u Republici
Hrvatskoj. Visinska mreža koju čine trajno stabilizirani reperi II. nivelmana visoke točnosti (II. NVT; 19701973) određuje se osnovom visinskog referentnog sustava Republike Hrvatske («Narodne novine», br.
110/04).
Iz samih definicija službenih visinskih sustava u Republici Hrvatskoj vidljivo je da je teško
očekivati njihovo podudaranje. Na slici 2. su zorno prikazana njihova međusobna odstupanja, i to na
mareografskim postajama od Kopra do Dubrovnika, čijim su mjerenjima određene srednje morske razine
koje definiraju novi visinski datum.
Slika 2: Srednja razina Jadrana u odnosu na N. N. Trsta (Jovanović, 1978)
Pošto u vrijeme izvođenja nivelmanskih radova na definiciji okosnice starog visinskog sustava
nisu postojali mareografi na koje se oslanja novi sustav, tek je nakon njihove instalacije i dovoljnog broja
godina registracije bilo moguće povezati ih na stari visinski sustav te dobiti razlike između starog datuma
- 115 -
i srednje morske razine u tim područjima. Uzme li se u obzir da je novi datum definiran srednjom
morskom razinom upravo na tim mareografima, može se reći da se ovom kontrolom dobila razlika u
datumima na mareografskim postajama između starog i novog visinskog sustava (slika 2).
Razlike prikazane na slici 2. izračunate su na način da je visina repera koji se nalazi u blizini
svake pojedine mareografske postaje određena na dva načina. Jednom iz njegove visine u odnosu na
srednju morsku razinu dobijenu na osnovu dugogodišnjih mareografskih mjerenja obližnjeg mareografa
(približna visina repera u novom sustavu), a drugi put povezivanjem repera geometrijskim nivelmanom
na službene repere povijesnog referentnog visinskog sustava (visina repera u starom sustavu). Za
naglasiti je da se radi o približnim visinama repera u novom sustavu, jer je srednja morska razina
određena iz dovoljnog broja godina, ali u drugom vremenskom periodu od perioda koji se koristio za
određivanje novog visinskog datuma, no njihove razlike u ovim razmatranjima mogu se zanemariti zbog
svog malog iznosa.
Praktično značenje prikazanih razlika vidljivo je iz službenih podataka repera za koje su dane
visine u oba sustava. Tako će primjerice visina nekog repera u području Splita u novom sustavu biti za
oko 31 cm manja u odnosu na njegovu visinu u starom sustavu. Nadalje, u području Zadra razlika
sustava iznosi oko 32 cm što se ne slaže sa slikom 2. To je stoga jer razlike vrijede samo u područjima u
kojima su prikazane i nije moguće izvršiti interpolaciju te dobiti razlike u nekom drugom području koje se
nalazi između navedenih mareografa. Razlog je nehomogenost u točnosti kojom je određena referentna
okosnica starog sustava.
Razlika između sustava je nastala iz više razloga. Osnovni uzroci su različito definirani datumi te
kvaliteta i obrada mjerenja kojima su definirane visinske referentne okosnice. Stari visinski datum
definiran je iz jednogodišnjih mjerenja mareografa u Trstu i vezan je uz epohu 1875. godine, dok je novi
datum određen na osnovu mjerenja pet mareografa iz punog perioda od 18.6 godina te je vezan uz
epohu 1971.5. Dio problema je u različitim epohama u kojima su datumi definirani, jer razdoblje između
tih epoha je gotovo stotinu godina, dok je dio u tome što je za definiranje starog datuma korišten samo
jednogodišnji period koji je te godine bio oko 12 cm niži od višegodišnjeg prosjeka.
Jedan visinski sustav, osim datumom, definiran je i svojom okosnicom koju čini polje stalnih
točaka stabiliziranih na terenu, čije su visine određene geometrijskim nivelmanom. Visinska okosnica
starog sustava definirana je mjerenjima APN-a, dok je novi sustav definiran mjerenjima II. NVT-a.
Bez obzira na sustavnost nivelmanskih mjerenja APN-a, podaci mjerenja nisu jedinstveno
izjednačeni, već je mreža izjednačena u nekoliko dijelova što je dovelo do nepravilnog nagomilavanja
pogrešaka te utjecalo na točnost nadmorskih visina repera.
Terenska mjerenja mreže II. NVT-a obavljena su sustavno u razdoblju od četiri godine, a
upotrebljen je unificirani instrumentarij i pribor te su jasno precizirani znanstveni i stručni kriteriji. Svi
podaci mjerenja obuhvaćeni su sustavnom računskom obradom i znanstvenom analizom, prema
suvremenim zahtjevima nivelmana visoke točnosti.
Iz činjenice da je stari datum oslonjen samo na jedan mareograf proizlazi zaključak da se
specifičnošću primijenjenih postupaka izjednačenja, te nagomilavanjem raznih sistematskih pogrešaka
pri mjerenjima APN-a, njegova apsolutna točnost udaljavanjem od Trsta pogoršava (slika 2), dok je novi
visinski datum oslanjanjem na pet mareografa uzduž istočne obale Jadrana jako dobro vezan uz srednju
morsku razinu. Još jedna od bitnih karakteristika novog sustava je homogenost njegove točnosti koja
omogućava kvalitetno određivanje srednje morske razine na cijeloj našoj obali odnosno crte SVVV nakon
primjene podataka HHI-a. Tome u prilog ide i činjenica da odstupanja visinskih razlika između susjednih
mareografa određenih mrežom II. NVT-a i mareografskim mjerenjima iznose maksimalno 2.7 cm
(Bilajbegović i dr., 1986) što upućuje na to da bi graf na slici 2. realnije izgledao sa srednjom morskom
razinom prikazanom kao os apscise.
4. ZAKLJUČAK
Bitan element pri evidenciji i obilježavanju pojasa pomorskog dobra čini crta SVVV. Točnost
određivanja crte SVVV najviše ovisi o položenosti morske obale. U slučaju obale koja blago pada
značajan utjecaj na točnost određivanja crte SVVV ima točnost određivanja visina - ukoliko se crtu želi
odrediti s točnošću od 0.5 m na obali pada 5%, visina SVVV mora biti određena bolje od 2.5 cm. Danas
različite nivelmanske metode dostižu visoke točnosti pri prijenosu visina, no pitanje je što je s našim
službenim visinskim sustavom koji je nastao prije više od stotinu godina i na čije repere se potrebno
osloniti pri određivanju visine SVVV.
Referentna ploha starog visinskog sustava pokazuje loše podudaranje sa SMR čemu je razlog
sam način određivanja datuma i visinske okosnice, čija je nehomogenost u točnosti nastala uslijed
specifičnosti obrade te kvalitete samih mjerenja. Novi visinski sustav, koji se do 2010. godine mora uvesti
u službenu upotrebu, pokazuje jako dobro podudaranje sa SMR te homogenost i visoku točnost.
- 116 -
Budući da dobro određen odnos između starog datuma i SMR imamo samo u područjima
mareografskih postaja koje su povezane na okosnicu starog sustava, teško je pretpostaviti što se s tim
odnosom događa u područjima koja se nalaze između tih postaja. Za razliku od toga, novi visinski sustav
s točkama svoje okosnice pruža kvalitetnu osnovu za određivanje crte SVVV na cijelom području naše
obale.
Radovi na evidentiranju pomorskog dobra još nisu predaleko odmakli pa bi trebalo razmotriti
odluku o određivanju okosnice novog visinskog sustava kao osnove za utvrđivanje crte SVVV. Ukoliko se
za određivanje razine SVVV odabere najjednostavnija metoda koja se koristi linearnom interpolacijom
između susjednih postaja, trebalo bi odlučiti mjerenja kojih mareografa će se koristiti pri određivanju
razlike geodetske nule i razine SVVV, te za te mareografe izračunati razine SVVV iz istog perioda kojim
je definiran i novi datum, da bi se izbjegao utjecaj trenda promjene morske razine.
LITERATURA
Bilajbegović, Asim i dr. (1987): II. nivelman visoke točnosti SR: Bosne i Hercegovine, Crne Gore,
Hrvatske, Slovenije i SAP Vojvodine, 1970-1973, Sveučilište u Zagrebu, Geodetski fakultet,
Zbornik radova, Niz D, Svezak broj 6/1
Feil, Ladislav i dr. (2003): Izrada dokumentacije neophodne za usvajanje službenog visinskog datuma
Republike Hrvatske, elaborat, Sveučilište u Zagrebu, Geodetski fakultet
Feil, Ladislav; Rožić, Nevio (2000): Prijedlog službenog visinskog datuma Republike Hrvatske, elaborat,
Sveučilište u Zagrebu, Geodetski fakultet
Jovanović, Božidar (1978): Izučavanje metoda mjerenja dubina mora, unapređenje obrade dubina i
definiranja obalne linije sa hidrografskog, geodetskog i pomorskog gledišta, disertacija,
Sveučilište u Zagrebu, Geodetski fakultet
Narodne novine (2003): Zakon o pomorskom dobru i morskim lukama 158/03
Narodne novine (2004): Uredba o postupku utvrđivanja granice pomorskog dobra 8/04
Narodne novine (2004): Odluka o utvrđivanju službenih geodetskih datuma i ravninskih kartografskih
projekcija Republike Hrvatske 110/04
Polli, Silvio (1960): Le propagazione delle maree nell' Adriatico. Atti del IX Convegno dell' Associazione
Geofisica Italiana, Roma, 1-11.
Roić, Miodrag; Racetin, Ivana (2003): Evidencije pomorskih područja, Geodetski list, broj 4, 279-290
- 117 -
- 118 -
STATUS OF EUVN AND EUVN_DA PROJECTS IN THE REPUBLIC OF CROATIA*
Ilija Grgić, Bojan Barišić, Mihajla Liker
ABSTRACT
The EUVN points are represent one basic element of the European geodetic infrastructure. They
serve as a control of the existing continental and national geoid solutions and for the estimation of height
datum differences. After the first analysis, discrepancies between gravimetric geoid EGG97 and the
point-wise EUVN geoid were detected due to errors in one of compared models. Croatian Geodetic
Institute (CGI) received all materials related to EUVN project from the State Geodetic Administration.
Analyse of the received materials shows that some height data, which have been sent to the EUREFUELN data centre, were calculated using benchmarks whose heights are in different height datum. This
paper represents discrepancies between EGG97 and EUVN after using uniform new official height datum
in Croatia – HVRS71 and densification project EUVN_DA on the territory of the Republic of Croatia.
KEYWORDS
EUVN, EUVN_DA
1. INTRODUCTION
EUVN project was completed in the year 2001 under the EUREF responsibility. It consists of
almost 200 points, which represent one basic element of the European geodetic infrastructure. EUVN
points serve as a control of the existing continental and national geoid solutions in ETRS89 and for the
estimation of height datum differences.
After the first analysis, discrepancies between gravimetric geoid EGG97 and the point-wise
EUVN geoid were detected due to errors in one of compared models. On the Croatian territory
discrepancy on only one point, HR05-Split, exceeds 50 cm and that point is marked as problematic
(Kenyeres et al. 2002), Fig. 1.1.
+1cm
+19cm
+23cm
+51cm
+15cm
+28cm
<1dm
>1dm
+67cm
0cm
0 10 20 30 40 50
100 km
Fig. 1.1. EGG97 and EUVN discrepancies on the territory of Croatia
Need of solving these problems is recognised and defined in two EUREF resolutions: No. 3
(June 2000) and No. 4 (May 2001). Result is project of EUVN densification - EUVN_DA and its aim is
solving the discrepancies problems and densification of EUVN points that will be used for sub-decimetre
accuracy connection of different national height networks in Europe. In combination with new European
održanom u Beču, Austria, 2.-5.6.2005. godine. Objavljeno u Zborniku radova Simpozija (u tisku).
*
- 119 -
gravimetric geoid it will contribute in analyses of the national levelling networks. Croatia, as member of
EUREF, has been called to contribute in densification project.
Priority of EUVN_DA project is realisation of dense and homogenous network of GPS/levelling
points. Expected distances between points should be from 50 to 100 kilometres. Special attention should
be given to areas where unexpected discrepancies are detected. New solution of European gravimetric
geoid is in preparatory phase and it should be finished in 2006. This solution includes new terrestrial
gravimetric data and improved satellite gravity models (CHAMP, GRACE). EGG2006 model and
EUVN_DA points will be used in combination for the production of a sub-decimetre accuracy height
reference surface consistent with ETRS89 and EVRS.
2. EUVN POINTS IN THE REPUBLIC OF CROATIA
Existing EUVN points in Croatia are established within EUVN GPS campaign that was carried
out 21-29 May 1997 under the Croatian State Geodetic Administration (SGA) responsibility. GPS
measurements had been performed on 11 points but only 8 points became official EUVN points
(Marjanović, Rašić 1998).
HR07
HR01
HR06
HR09
HR02
HR10
HR04
HR08
Official EUVN station
Additional EUVN station
HR05
HR12
0 10 20 30 40 50
HR03
100 km
Fig. 2.1. EUVN points established in 1997 GPS campaign
2.1. VERIFICATION OF CROATIAN EUVN DATA
Croatian Geodetic Institute (CGI) was established after the EUVN GPS campaign had been
finished. CGI received all data related to 8 official and 3 additional points with intention to make project of
densification on Croatian territory. All official and additional points should have been connected by first
order levelling to the nearest primary levelling network benchmarks. Levelling data were taken from the
report “Preparatory works for participation of the Republic of Croatia in the European project - EUVN”
(Čolić, 1997). For some points the CGI did not receive levelling data and for all points gravimetric
measurements were not carried out. For this reasons full verification of EUVN data is not possible.
Based on received data some works in suspected points should be repeated. Gravimetric
measurements will be carried out at all points.
This is the time when Croatia is replacing old vertical reference system (HVRS1875) with the
new one (HVRS71). Accidentally in data centre were sent inhomogeneous levelling data. For points
HR02 Brusnik, HR04 Gradište and HR08 Plitvice, used benchmarks heights were in old vertical
reference system and for HR01 Bakar, HR03 Dubrovnik, HR06 Zagreb and HR07 Rovinj those heights
were in new system. Because of missing data for point HR05 Split was impossible to find out which
benchmark and system were used.
Table 2.1.1. shows that discrepancies between EUVN and EGG97 were reduced after
homogenisation of used benchmarks heights (Fig. 2.1.1.).
Discrepancies at some points are higher than expectations so levelling will be repeated at points
HR01 and HR07. Also measurements will be repeated at the point HR05.
Connections of EUVN points with the official vertical network were completed in the same time
with EUVN GPS campaign 1997. In the 2000 official data of Croatian vertical network integration in
- 120 -
UELN have been received (Feil, Rožić, 2000). Heights of all levelled points now should be expressed as
UELN heights.
Table 2.1.1. Discrepancies between EUVN and EGG97 geoid
EUVN
Point
HR01 Bakar
HR02 Brusnik
HR03 Dubrovnik
HR04 Gradište
HR05 Split
HR06 Zagreb
HR07 Rovinj
HR08 Plitvice
Connec.
Vert. ref. system
Benchmar
Homogenisatio
of sent data
n
k
32
MXV
A-496
6
FR3020
BP82
22264
HVRS71
HVRS71
HVRS1875
HVRS71
HVRS71
HVRS71
HVRS1875
HVRS71
Imposible to reconstruct
HVRS71
HVRS71
HVRS71
HVRS71
HVRS1875
HVRS71
Diff. of
benchmark
heights
[m]
EUVN and EGG97
discrepancie from
sent data
[m]
EUVN and EGG97
discrepancie after
homogenisation
[m]
0.0000
0.1468
0.0000
0.2589
0.51
0.19
0.00
0.23
0.67
0.01
0.15
0.28
0.51
0.04
0.00
-0.03
0.01
0.15
0.06
0.0000
0.0000
0.2152
+1cm
+4cm
-3cm
+51cm
+14cm
+6cm
<1dm
>1dm
+67cm
0cm
0 10 20 30 40 50
100 km
Fig. 2.1.1. EGG97 and EUVN discrepancies after the homogenisation
3. DENSIFICATION ACTION EUVN_DA IN CROATIA
Plan of densification completely rely on existing 8 official EUVN sites in Croatia. Three additional
points that were measured in campaign 1997 will be included in densification because they have 7 days
of GPS measurements and solid monumentation. Densification was planned with respects to geoid figure
in region, suspicious EUVN and EGG97 discrepancies on official EUVN sites and present densification
projects in neighbouring countries.
To check coincidence of planned densification sites with specifications (expected distances
between points should be from 50 to 100 kilometres), circles of 50 kilometres radius are drown, Fig. 3.1.
Little parts of territory, between points HR06 and HR09 is not covered due to primary levelling network
configuration and between points HR09 and HR14 due to Hungarian plan of densification. If Hungarian
plan changes, there will be no significant impact on Croatian densification quality. In some areas network
is denser than prescriptions because of more complex geoid figure in that parts.
Official EUVN points and planned densification points create uniform network on the Croatian territory
Fig. 3.1.
In preparatory phase of densification action next works had been done (Grgić, Barišić 2004):
•
Project preparation,
•
Fundamental geodetic points data acquisition (benchmarks, gravimetric points, GPS and
trigonometric points),
•
Production of data base that is necessary for densification planning,
•
Recognition and see over of potential sites.
Except the planning of densification for the project realisation is necessary to do next works:
- 121 -
•
GPS measurements on the points where needed and processing of measurements with a
scientific software package according to the EUREF standards,
•
Connection of the points to the nearest UELN benchmarks by the first order levelling and
measurements adjusting,
•
Gravimetric measurements on the all densification points because of the technically and
scientifically correct estimation of the heights in geopotential and normal system of UELN,
•
Compilation of the official forms with the EUVN_DA points information,
•
Productions of technical report that will be send to the SGA.
SI02
SI01
HR16
HR06
SI03
IT10
Hr9
HR02
HR14
HR01
Hr10
HR15
HR07
HR04
HR17
HR08
HR18
HR21
Official EUVN point
Additional EUVN point
Planned densification point
HR19
HR20
HR05
HR22
Hr12
HR03
Fig. 3.1. EUVN and planned EUVN_DA points
HR16
GPS m.
levelling
gravimetric m.
site description
0 10 20 30 40 50
100 km
Fig. 3.2. Planned works on the EUVN and EUVN_DA points
- 122 -
Existence of the solid monumentation and acceptable GPS, levelling or gravimetric
measurements, vicinity of primary levelling network were major conditions for the selection of
densification points. Examples of such points are HR19 Posedarje that is primary levelling network
benchmark suitable for GPS measurements, HR21 Strmica first order gravimetric point suitable for GPS
measurements in vicinity of the primary levelling network benchmark, HR16 Štefanovec with solid
monumentation suitable for GPS measurements in vicinity of the primary levelling network benchmark
Fig. 3.3.
Fig 3.3. EUVN_DA points HR16 and HR 21
3.1. GPS, LEVELLING AND GRAVIMETRIC MEASUREMENTS
On purpose to eliminate daily changes in height component, shortest period of measurements
should be 24 hours. All GPS measurements will be carried out in accordance with the 1997 campaign
specifications supplemented with the EUVN_DA recommendations (Torres, Kenyeres, 2002).
Final solution coordinates will be delivered in ETRS89 system or ITRFyy frame. Additional
information will be delivered in official forms.
The EUVN_DA points will be connected to nearest primary levelling network benchmarks by the
first order levelling. Because of the accuracy and economical aspects, EUVN_DA points are chosen
close to the primary levelling network benchmarks.
In the Republic of Croatia the fundamental gravimetric network was established few years ago.
The network consists of 5 absolute gravimetric points and 36 points of the first order (Bašić et al., 2004).
Gravimetric measurements are necessary for correct estimation of the EUVN_DA points heights in
geopotential and normal system of UELN. The method of profiles, Fig. 3.1, will be used for gravimetric
measurements.
1
2
3
4
5
Fig. 3.1. The method of profiles
4. CONCLUSION
The project of densification - EUVN_DA in Croatia is result of systematic preparatory works.
Planning of densification started after the CGI had received all materials related to the EUVN project.
The project concerns requirements for sub-decimetre accuracy connection of different national height
networks in region and for analyses of the national levelling network. Priority of the project is realisation
of dense and homogenous network that will be used as base for future improvements of European geoid
models.
Some levelling data from EUVN 1997 campaign have to be corrected and gravimetric
measurements on the all EUVN and EUVN_DA points have to be done. The national primary levelling
network has been integrated within the UELN and prerequisite for estimation of the EUVN and
EUVN_DA points heights in geopotential and normal system of UELN are satisfied.
The densification project will improve next geoid models realizations on territory of Croatia and
also clear misunderstandings of discrepancies at some official EUVN points.
- 123 -
REFERENCES
Bašić, T., et al. (2004): Osnovna Gravimetrijska mreža Republike Hrvatske, Faculty of Geodesy, Zagreb.
Čolić, K. (1997): Pripremni radovi za sudjelovanje Republike Hrvatske u europskom projektu “Europska
vertikalna referentna mreža” (EUVN), Faculty of Geodesy, Zagreb.
Čolić, K. Gojčeta, B. et al. (1997): EUVN 1997 GPS Campaign in Croatia, Faculty of Geodesy, State
Geodetic Administation, Zagreb.
Feil, L., Rožić, N. (2000): UELN geopotencijalni i normalni visinski sustav Republike Hrvatske, Faculty of
Geodesy, Zagreb.
Grgić, I., Barišić, B. (2004): Projekt progušćenja EUVN mreže (EUVN_DA), Croatian Geodetic Institute,
Zagreb.
Kenyeres, A., Ihde, J., et al. (2002): EUREF Action for the Densification of the EUVN Network, Presented
at the EUREF Symposium in Ponta Delgada.
Marjanović, M., Rašić, Lj. (1998): Results of the EUVN 1997 GPS Campaign in Croatia, Paper
presented at the Second International Symposium Geodynamics of the Alps-Adria Area by
means of Terrestrial and Satellite Methods, Dubrovnik.
Torres, J. A., Kenyeres, A. (2003): Densification Action for the European Vertical Reference Network
(EUVN_DA), EUREF form letter.
- 124 -
DIGITALNI ORTOFOTO U REPUBLICI HRVATSKOJ I U SVIJETU:
NORME I STANJE U PRAKSI*
Višnja Miloš
SAŽETAK
U ovom radu opisuju se teoretske postavke, način izrade i svrha prvih radova na području
redresiranja, izrade fotoplana te ortofotoplana.
Nakon teoretskih osnova dan je opis izrade digitalnih ortofotokarata danas, važeći pravilnici u
Republici Hrvatskoj vezani uz njihovu izradu te pregled softvera i hardvera koji se danas koristi u izradi
digitalnih ortofotokarata u Republici Hrvatskoj.
Opisana su iskustva na izradi digitalnog ortofota i način prezentiranja izrađenih listova digitalne
ortofotokarte na internetskim stranicama u nekim državama Europe i u Sjedinjenim Američkim
Državama.
Provedena su dva ispitivanja kvalitete digitalnih ortofotokarata u Republici Hrvatskoj. Prvim
ispitivanjem trebalo je ustanoviti postoji li veza densitometrijskih vrijednosti zacrnjenja filma i vrijednosti
histograma digitalnih zapisa pripadnih listova digitalne ortofotokarte. Drugim ispitivanjem, položajno se
uspoređuju detalji preslikani na digitalnoj ortofotokarti i identični detalji na odgovarajućim listovima
Osnovne državne karte/Hrvatske osnovne karte. Uz opis i ocjenu svakog pojedinog procesa izrade
digitalne ortofotokarte dan je prijedlog na koji bi se način povećala njihova pouzdanost izrade i postigla
bolja kvaliteta.
Na kraju rada, dan je pregled nekih osnovnih i za fotogrametriju važnih novosti u načinu
prikupljanja podataka, kao što su digitalne kamere za snimanje iz zraka, lidarski i radarski sustavi, GPSom (eng. Global Positioning System) podržano snimanje iz zraka, te satelitske snimke visoke rezolucije.
ABSTRACT
In this work the theoretical foundation, the purpose and the way of the first labors in the area of
orthophoto production are described.
After theoretical basics, the decription of the way of today´s production of orthophoto maps, the
valid specificatons in the Republic of Croatia considering the orthophoto production, are given. Also, the
review of the actual softwer and hardwer which is today in use in the Republic of Croatia, is illustrated.
The following, is the decription of the experiances in the orthophoto production and the way of
presenting orthophoto maps on the Internet sites in some countries in Europe and in the United States.
Two investigations of the quality of the orthophoto maps in the Republic of Croatia are described.
The aim of the first investigation was to check if there is connection between densitometric values of film
density and the belonging histogram values of the digital orthophoto maps. With the second
investigation, the position of the details on the digital orthophoto maps is checked against position of the
coresponding details on the sheets of the Basic state map/Croation basic map. With description and the
mark of each proces of the orthophoto production, the proposal how the accuracy and the quality of the
digital orthophotos could be better, is given.
At the end of this work, the overview of some basic and for photogrammetry important news in
the way of collection data, like the digital camera for aerorecording, lidar and radar systems, the airborne
GPS and satellite images of high resolution, are described.
*
Magistarski rad obranjen na Geodetskom fakultetu Sveučilišta u Zagrebu 25.11.2005. godine.
- 125 -
- 126 -
POPIS AUTORA
Autor
Institucija
Željko Bačić, prof. dr. sc.
Državna geodetska uprava Republike Hrvatske
Sjedište
Zagreb
Bojan Barišić, dipl. ing. geod.
Zagreb
Tomislav Bašić, prof. dr. sc.
Geodetski fakultet Sveučilišta u Zagrebu
Zagreb
Stanislav Frangeš, prof. dr. sc.
Zagreb
Ilija Grgić, mr. sc.
Zagreb
Željko Hećimović, dr. sc.
Zagreb
Slavko Lemajić, dipl. ing. geod.
Zagreb
Mihajla Liker, dipl. ing. geod.
Zagreb
Danko Markovinović, mr. sc.
Zagreb
Višnja Miloš, mr. sc.
Zagreb
Stipica Pavičić, mr. sc.
Hrvatski geodetski institut (do listopada 2004. godine)
Zagreb
Mladen Rapaić, dipl. ing. geod.
Hrvatski geodetski institut (do studenog 2004. godine)
Zagreb
Nevio Rožić, prof. dr. sc.
Hrvatski geodetski institut (do siječnja 2006. godine)
Zagreb
Ivica Vilibić, dr. sc.
Institut za oceoanografiju i ribarstvo
Split
INDEX AUTORA I RADOVA
Autor
Članak
Str.
Bačić, Ž.
Cambridge Conference 2003 "National mapping – shaping the future"
Barišić, B.
European vertical reference network (EUVN) considering Champ and Grace gravity models
Status of EUVN and EUVN_DA projects in the Republic of Croatia
81
113
119
Bašić, T
Status of the Croatian first order gravity network
Visinska kontrola geodetskih i kartografskih proizvoda u procesu topografske i katastarske izmjere
33
101
47
Frangeš, S.
Creating the toponymic database of the Republic of Croatia - project Toponimis as sub-project of Stokis
Grgić, I.
Specifičnosti geodetske osnove u tunelogradnji
71
81
101
107
113
119
Liker, M.
119
Hećimović, Ž.
Stabilnost mjernog sustava SCINTREX HGI-2 gravimetra
Lemajić, S.
Croatian-Norwegian geoinformation project
Improvement of quality control system in Croatia
Topographic data production as basis for NSDI – Croatian example
Markovinović, D.
Stabilnost mjernog sustava SCINTREX HGI-2 gravimetra
Miloš V.
Digitalni ortofoto u Republici Hrvatskoj i u svijetu: norme i stanje u praksi
Pavičić, S.
91
Rapaić, M.
Creating the toponymic database of the Republic of Croatia – project Toponimis as sub-project of Stokis
51
57
65
91
Rožić, N.
Croatian geodetic institute
Accuracy of geometric levelling networks at the terrritory of Croatia
Točnost visinske osnove geometrijskog nivelmana na teritoriju Republike Hrvatske
Strategy and system of QC of the official geographic data produced by private companies in Croatia
Cambridge Conference 2003 "National mapping – shaping the future"
Changes of bench mark heights being the consequence of introducing the new Croatian height system
7
9
11
25
33
41
47
51
57
73
Vilibić, I.
- 127 -
65
17
33
81
51
57
91
101
107
17
33
107
125
113

zbornikradova - Geodetski fakultet Sveučilišta u Zagrebu

Transcription

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