AN OVERVIEW OF A NEW CHINESE WEATHER SATELLITE FY-3A

AN OVERVIEW OF A NEW
CHINESE WEATHER SATELLITE FY-3A
by
Chaohua Dong, Jun Yang, Wenjian Zhang, Zhongdong Yang, Naimeng Lu,
Jinming Shi, Peng Zhang, Yujie Liu, and Bin Cai
The on-orbit Chinese polar-orbiting meteorological satellite FY-3A (second generation)
is able to provide sounding and image data to users worldwide.
Fig. 1. Schematic diagram of FY-3A spacecraft.
M
eteorological satellites have become an irreplaceable weather and ocean observing tool
in China. These satellites are used to monitor
natural disasters and improve the efficiency of many
sectors of our national economy. It is impossible to
ignore the space-derived data in the fields of meteorology, hydrology, and agriculture, as well as disaster
monitoring in China, a large agricultural country.
For this reason, China is making a sustained effort
to build and enhance its meteorological observing
system and application system. The first Chinese
polar-orbiting weather satellite Feng-Yun (FY-1A) was
launched in 1988. Since then China has launched 10
meteorological satellites, 
5 (FY-1A/B/C/D and FY-3A) of
Table 1. FY-3A satellite specifications and major orbital parameters.
which are sun synchronous and
Orbit
Sun synchronous
5 of which (FY-2A/B/C/D/E) of
Altitude (km)
831
which are geostationary satellites; China will continue its two
Power
1100 W
types of meteorological satellite
Launch mass
2298.5 Kg
programs. A low-inclination
4.38 × 2.0 × 2.0 m (in stowed)
orbit satellite is planned, mainly
Size
4.44 × 10.0 × 3.79 m (in flight)
for precipitation measurements
Orbital period (min)
101.49
(mainly radar and passive microwave measurements). The
Inclination (°)
98.81
FY-3 series is more powerful
Eccentricity
<0.0013
than the FY-1 series (the Chinese
Local time at descending node
1005 UTC
first-generation satellite), beOrbital maintenances
15 min (2 yr) −1
cause it has sounding capabiliOnboard data storage
144 GB
ties and natural color imagery
Attitude control
Three-axis stabilization
with a higher spatial resolution
of 250 m. The FY-3A spaceQuasi-repeat time
5 days
craft carries 11 instruments,
Launch vehicle
LM-4B
namely, the Visible and Infrared
Design life
3 yr
Radiometer (VIRR), Medium
Resolution Spectra l Imager
(MERSI), Microwave Radiation Imager (MWRI), and space weather monitoring. The characteristics of
Total Ozone Mapping Unit (TOU), Infrared Atmo- the FY-3A orbit, primary environmental sensors, and
spheric Sounder (IRAS), Microwave Atmospheric products are introduced in this paper. The FY-3A data
Temperature Sounder (MWTS), Microwave Atmo- and products are available to users worldwide.
spheric Humidity Sounder (MWHS), Solar Backscatter Ultraviolet Sounder (SBUS), Solar Irradiation FY-3 MISSIONS. As a new generation of polarMonitor (SIM), Earth Radiation Measurer (ERM), orbiting meteorological satellite, the FY-3 series conand Space Environment Monitor (SEM). Compared sists of two experimental and at least four operational
with the FY-1 series, all of the instruments except satellites. The FY-3 series is expected to have a service
VIRR and SEM are newly developed. The spectral life until 2020. FY-3A is a research and development
bands of those instruments cover violent, visible, (R&D) satellite. The primary missions of the FY-3
near-infrared, infrared, and microwave regions. are as follows:
Potential applications of the FY-3A observations include numerical weather prediction, climate research, • global sounding of three-dimensional thermal and
environment monitoring, natural hazard monitoring,
moisture structures of the Earth’s atmosphere,
measuring cloud properties, and other key parameters, such as precipitation, ozone, etc., to
support global numerical weather prediction and
AFFILIATIONS: Dong , Yang , Zhang , Yang , Lu, S hi ,
P. Zhang, Liu, and Cai —National Satellite Meteorological
environmental services;
Center, China Meteorological Administration, Beijing, China;
• global imaging of the Earth’s surfaces to monitor
W. Zhang —Observing and Information Systems Department,
large-scale meteorological and/or hydrological
World Meteorological Organization, Geneva, Switzerland
disasters and the biosphere environment;
CORRESPONDING AUTHOR: Chaohua Dong, National Satellite
•
establishing
long-term environmental datasets
Meteorological Center, China Meteorological Administration,
with important geophysical parameters for climate
Beijing 100081, China
monitoring, global prediction, and Earth science
E-mail: dchua@nsmc.cma.gov.cn
research; and
The abstract for this article can be found in this issue, following the
•
collecting
and retransmitting data by data collectable of contents.
tion
platforms
(DCPs).
DOI:10.1175/2009BAMS2798.1
In final form 22 April 2009
©2009 American Meteorological Society
1532 |
october 2009
FY-3A SPACECRAFT. FY-3A is a sun-synchronous
polar-orbiting environmental satellite. The satellite
Table 2. FY-3A major remote sensing instruments. All spatial resolutions are for subsatellite points.
Instrument name
Major characteristics
Primary use
Sounding mission
IRAS
Spectral range: 0.69 ~ 15.5 μm, channel
numbers: 26, cross-track scanning: ±49.5°
(2172 km), spatial resolution: 17.0 km
Atmospheric temperature profile, atmospheric
humidity profile, total ozone content, cirrus,
aerosol, etc.
MWTS
Frequency range: 50 ~ 57 GHz, channel
numbers: 4, cross-track scanning: ±48.6°
(2088 km), spatial resolution: 50 ~ 75 km
Atmospheric temperature profile, rainfall, cloud
liquid water, surface parameters, etc.
MWHS
Frequency range: 150 ~ 183 GHz, channel
numbers: 5, cross-track scanning: ±53.38°
(2692 km), spatial resolution (SSP): 15 km
Atmospheric humidity profile, water vapor,
rainfall, cloud liquid water, etc.
TOU
Spectral range: 309 ~ 361 nm, channel
numbers: 6, cross-track scanning: ±56.0°
(3020 km), spatial resolution: 50 km
Total ozone distribution
SBUS
Spectral range; 252 ~ 340 nm, channel
numbers: 12, spatial resolution: 200 km
Ozone profile, total ozone amount
VIRR
Spectral range: 0.44 ~ 12.5 μm, channel
numbers: 10, cross-track scanning: ±55.4°
(2916 km), spatial resolution: 1.1 km
Cloud, vegetation, snow and ice, SST, LST,
water vapor, aerosol, ocean color, etc.
MERSI
Spectral range: 0.41 ~ 12.5 μm, channel
numbers: 20, cross-track scanning: ±55.4°
(2916 km), spatial resolution: 0.25 ~ 1 km
True color imagery, cloud, vegetation, snow
and ice, ocean color, aerosol, rapid response
products (fires, flooding, etc.)
MWRI
Frequency range: 10.65 ~ 89 GHz, channel
numbers: 10 (5 frequencies with H, V polarization), conical scanning: 110.8° (1430 km),
spatial resolution: 15–80 km
Rainfall, soil moisture, cloud liquid water, sea
surface parameters
Ozone mission
Imaging mission
in general is a hexahedron of 4.4 × 2.0 × 2.0 m. The
total weight is about 2300 kg. The one solar panel
is mounted on one side of the satellite main body,
which makes the span length of the satellite 10 m in
flight. The attitude control of the satellite is three
axis stabilized with a measuring precision of 50 m,
with the measurement of the star sensor onboard the
satellite. Table 1 depicts the major orbital parameters
of the satellite. Figure 1 is a schematic diagram of
the spacecraft, showing the instrument-mounting
platform, the solar array, and the transmitting and
receiving antennas. The spacecraft communication
links are S, L, and X band. Commands are via S band
only. Command and telemetry links are active simultaneously. The S-band section of the communications
subsystem provides primary telemetry and command
(T&C) service to and from the FY-3A ground stations.
The L- and X-band sections of the communication
subsystem provide the science and engineering data
downlink for the FY-3A common spacecraft. Users
AMERICAN METEOROLOGICAL SOCIETY
in the world can directly receive the MERSI data and
the other instruments’ data from the spacecraft in
real time. The satellite science data downlink follows
the Consultative Committee for Space Data Systems
(CCSDS) space data system standards, which makes
the FY-3A data format compatible with the National
Polar-orbiting Operational Environmental Satellite
System (NPOESS) and Meteorological Operational
Satellite Programme (MetOp) satellite data transmission characteristics. There are 11 instruments
aboard the FY-3A spacecraft. Table 2 summarizes the
primary environmental sensor characteristics. A brief
introduction to each sensor follows.
Sounding mission. I nfrared Atmospheric S ounder .
This is the primary sounder for FY-3A. It is a High
Resolution Infrared Radiation Sounder (HIRS)/3-like
(Ceckowski et al. 1995) instrument [National Oceanic
and Atmospheric Administration (NOAA) K, L,
and M satellites (KLM) user’s guide; Robel (2006)].
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However, there are a total of 26 channels in this IR
sounder. The first 20 channels are almost the same as
HIRS/3, while the 6 additional channels will enable
IRAS to measure aerosols, carbon dioxide content,
and cirrus. The instrument ground instantaneous
field of view (IFOV) is 17 km at nadir; see Table A1 in
the “Sounding mission” appendix for details. A new
infrared interferometer for FY-3E is planned.
Microwave Atmospheric Temperature Sounder. This is
a four-channel passive scanning microwave sounder
for the purpose of temperature sounding in cloudy
regions. There are four channels around 50 GHz.
Table A2 in the “Sounding mission” appendix shows
the major specifications of MWTS. It is planned that
the MWTS will be improved during FY-3C’s development; the temperature sounding channels will
be increased to 13 channels, providing temperature
information for more atmospheric layers.
M icrowave Atmospheric H umidity S ounder . This
instrument is similar to the Advanced Microwave
Sounding Unit (AMSU)-B (Klaes 1995), with a
primary purpose of moisture sounding in cloudy
regions. There are five higher-frequency channels
(150–183 GHz); the 150-GHz channel is polarized in
both the vertical and horizontal direction. MWHS
has a nominal IFOV of 15 km on surface at nadir.
Table A3 in the “Sounding mission” appendix summarizes the instrument specifications. It is planned
that the MWHS will be improved for FY-3D. A threechannel in the 118-GHz band will be added to the
original MWHS during FY-3D development.
IRAS, together with MWTS and MWHS, provides
global atmospheric temperature and moisture profiles
(Smith and Woolf 1976) in all weather conditions
for global numerical weather prediction models and
climate data records.
Ozone mission. Two instruments, the SBUS and TOU,
are new sensors onboard FY-3A for measuring atmospheric ozone distribution. TOU is mapped by a
six-channel spectrometer with wavelengths from 308
to 360 nm, with a resolution of 50 km at nadir. The
profiler is a 12-channel spectrograph with wavelength
coverage of the spectrograph extending from 252 to
380 nm. The spatial resolution of the ozone profile
is around 200 km at nadir. Detailed information
for the two sensors is given in the “Ozone mission”
appendix.
The Earth Radiation Measurement. This instrument
is very much like the Earth Radiation Budget Ex1534 |
october 2009
periment (ERBE) instrument onboard the NOAA
satellites. There are wide-FOV and narrow-FOV
observation units, separately, with two channels on
each of the units. The broadband channel covers the
spectral range from 0.2 to 50 μm, and the narrowband
channel covers 0.2–4.3 μm, see the “Earth radiation
measurement” appendix for details.
Imaging instruments. Visible and Infrared R adiometer.
This is an instrument with heritage from the Multichannel Visible and Infrared Scanning Radiometer
(MVISR; 10 channels) onboard the FY-1C/D satellites.
Indeed, this 10-channel radiometer makes operational observations from FY-3A. For risk reduction
purposes, this instrument remains the same as the
MVISR on FY-3A.
Medium Resolution Spectral Imager. Referring to the
Moderate Resolution Imaging Spectroradiometer
(MODIS) onboard the Earth Observing System (EOS)
satellite series, this instrument has 20 channels for
the FY-3A satellite. The MERSI channels are mainly
located in visible (VIS) and near-IR (NIR) spectral
regions while the Visible and Infrared Radiometer
(VIRR) instrument has the important IR channels.
These two instruments complement each other. The
IR bands from MERSI and VIRR can also be used
together with radiance measurements from sounding
instruments for handling clouds in atmospheric profiling (Li et al. 2005). MERSI has five channels (four
VIS and one thermal IR), with a spatial resolution
of 250 m, which enables imaging of the Earth with
high resolution in natural color during the day and
high-resolution thermal IR imaging during the night.
The MERSI channel specifications are summarized in
Table D2 in the “Imaging instrument” appendix. It is
planned that MERSI will be improved during FY-3D
development. Five to six IR window channels will be
added, and the VIRR will be removed.
Microwave Radiation Imager. This is a conical scanning
microwave imager at five frequency points with dual
polarizations (10 channels). This sensor measures
thermal microwave missions from land and ocean
surfaces, and can measure various forms of water in
the atmosphere, clouds, and surfaces. Because microwave wavelengths are much longer in the electromagnetic spectrum compared with visible and infrared
wavelength, and at some channels the wavelengths
can be longer than 1 mm, the imager can penetrate
clouds, and provides forecasters with an all-weather
measurement capability. At higher-frequency channels, such as 89 GHz, the scattering signature from
the cloud and precipitation are also good indicators
for detecting rainfall over both land and ocean. The
spatial resolutions are from 12 to 80 km, depending
on the wavelengths. Table D3 in the “Imaging instruments” appendix shows the major specifications of
the MWRI instrument.
Space environment monitoring unit. The SEM onboard
FY-3A is a modified version of the FY-1 space environment monitoring instruments, with improved
accuracy and measuring capacity for high-energy
particles (see the “Space environment monitoring
unit” appendix for details).
PRODUCTS AND POTENTIAL APPLICATIONS. Products. A completely new ground system
has been developed for FY-3A data receiving, processing, storage, and product dissemination since the
year 2007. The calibrated and Earth-located FY-3A
sensor data are called level-one (L1) data, with full
resolution that is the same as that of the instrument.
It is mainly for numerical prediction model use and
further product generation. The atmospheric and
geophysics parameters, called level-two (L2) data,
are derived by using scientific algorithms based on
the level one data. These L2 data are used for weather
analysis, and environment and nature disaster
monitoring. The 10-day, monthly, and yearly mean
products are called level-three (L3) data, which are
mainly for climate analysis. All of the products are
constructed in hierarchical data format (HDF) and
are easy for users to extract and display. The products
are as follows:
1) Atmosphere and cloud products: atmospheric
temperature and humidity profiles, atmospheric
stability index, total precipitable water, cloud
mask, cloud-top temperature, cloud type, cloud
optical thickness, etc. (see Table 3 for details);
2) Land and sea surface products: vegetation index,
land cover (vegetation type), snow cover, land
surface reflectivity and temperature, flooding
index, global fire points, sea surface temperature,
ocean color/chlorophyll, and sea ice cover (specific products are listed on Table 4);
3) Space weather products: solar proton, solar ion,
solar electron, potential, radiant dose, and single
event.
Table 3. Primary operational products for atmosphere and cloud.
No.
Products
Resolution (km)
Coverage
Accuracy
1
Cloud mask
1
Granule
5% –20%
2
Cloud-top temperature
5
Granule
0.5–2.0K
3
Cloud-top height
5
Granule
50 hPa
4
Cloud optical thickness
5
Global
5% –20%
5
Cloud type
5
Global
5% –20%
6
Cloud cover (total amount, high
cloud)
5, 10
Global
5% –20%
7
Outgoing longwave radiation at TOA
5, 50 17
Global
3–8 W m−2
8
Aerosol over ocean
1, 10
Ocean
15% –30%
9
Fog detection
1
Granule
rms < 0.25
10
Total precipitable water
1, 5, 50, 27 × 45
Land, ocean
15% –25% 10% –20%
11
Precipitation rate at the ground
18 × 30
Global
30%
12
Atmospheric temperature profile
1000–10 hPa
50
Global
1.5–2.5 K
13
Humidity profile 1000–300 hPa
50
Global
15% –25%
14
Geopotential height 1000–10 hPa
50
Global
15
Atmospheric stability index
50
Global
16
Total ozone
50, 17
Global
8% –15%
17
Ozone profile
200
Global
8% –15%
18
Flux at TOA from ERM scanner
35
Orbit/regional/global
LW: 10 W m−2 SW: 30 W m−2
19
Flux at TOA from ERM non scanner
120°
Orbit
LW: 10 W m−2 SW: 30 W m−2
AMERICAN METEOROLOGICAL SOCIETY
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Table 4. Primary operational products for land and sea surface.
No.
Products
Resolution
Coverage
Accuracy
1
Vegetation index, normalized differential
vegetation index
250 m, 1 km
Global
5% –10%
2
Land cover (Vegetation type)
250 m, 1 km
Global
15% –20%
3
Snow cover
1 km, 5 km
Global
10% –20%
4
Land surface reflectivity
250 m, 1 km
Global
TBD
5
Land surface temperature
1, 25, 50 × 85 km
Global
1.0–2.0 K
6
Flooding index
50 × 85, 25 km
Global
TBD
7
Global fire area
1 km
Global
5%
8
Sea surface temperature
1, 5, 50 km
Global ocean
1.0–1.5 K
9
Ocean color/chlorophyll
1 km, 10 km
Global ocean
15% –20%
10
Sea ice cover
250 m, 1 km
Global ocean
5% –15%
Fig. 2. The assimilation results of FY-3A sounding data.
Potential applications. Here some data products are
given as examples for FY-3A potential applications.
The sounding data assimilation test. The radiances
observed from MWTS from 1 to 20 December 2008
are used in the Global/Regional Assimilation and
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Prediction System (GRAPES) three-dimensional
variational data assimilation (3DVAR) system (Xue
and Cheng 2008). The results of geoheights at 500 hPa
have a positive impact compared with those without
FY-3A data, especially in the Southern Hemisphere.
The regional sounding data assimilation is also
Fig. 3. (a) Geoheight analysis field at 500 hPa of ECMWF and (b) prediction of NCEP without assimilating FY3A.
Fig. 4. Nuri typhoon monitoring (22 Aug 2008) using
(a) MERSI and (b) MWHS data.
tested. In the study, 10-day radiances from the three
sounding instruments (IRAS, MWTS, and MWHS)
over the west part of China from 20 to 30 August are
used because there are a few ground stations in that
area. The Weather Research and Forecasting (WRF)
3DVAR system is used for the test. The assimilation
results indicated in Figs. 2a–d are the assimilation of
MWTS, MWHS, IRAS + MWHS, and IRAS + MWTS
+ MWHS, respectively. In order to see the impact,
the European Centre for Medium-Range Weather
Forecasts (ECMWF) geoheight analysis field at
500 hPa at 1200 UTC 27 August is taken as truth, see
Fig. 3a. Figure 3b is the same as Fig. 3a, but without
assimilating FY-3A data. The comparisons of each
assimilation show that all tests have a positive impact,
AMERICAN METEOROLOGICAL SOCIETY
but the impact is more positive with MWHS, and the
impact is the most positive when all three sounding
instruments are included in this case study.
Typhoon monitoring. Figure 4 shows Typhoon Nuri
located at 21.5°N, 115.1°E, close to the coast in a MERSI
visible image with a resolution of 250 m (Fig. 4a) and
MWHS 150-GHz brightness temperature at 0200 UTC
22 August 2008. The strong convective area is in the
southern eye of Nuri over the ocean (Fig. 4a), and the
corresponding blue color area in the microwave image
may indicate rainfall. Figure 5 is a global image mosaic
from MERSI with natural color and a resolution of
3 km. It can be used for weather system, land surface
analysis, and typhoon monitoring.
october 2009
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Get FY-3A data. There are
several ways for users to get
FY-3A data and products.
First, FY-3A spacecraft have
a direct broadcast system
for real-time broadcasting
of the science and engineering data of MERSI and
the rest of the FY-3A sensor
data. Users in the world can
receive High Resolution
Picture Transmission and
Mission Picture Transmission (HRPT&MPT)/FY-3A
Fig. 5. A global image mosaic from MERSI with natural color and resolution
data by their own receiving
of 3 km.
facility. The international
S urface characteristic monitoring . Figure 6 is a software package for processing the raw data of FY-3A
global image of the land surface temperature image and generating L1 data is under development now and
generated using MWRI data. This kind of product is will be available in about 3–4 months. Second, users
compensation for using inferred data in a cloudy re- can get data products through the FENGYUNcast
gion and can be used in land surface assimilation and system operated by the National Meteorological
as an input to retrieve soil moisture. Figure 7 shows Information Center (NMIC) of the China MeteoGreenland sea ice monitoring with MERSI 250-m rological Administration (CMA), if they are within
datasets on 16, 23, 31 July and 31 August 2008. The the broadcast range of telecommunication satellites.
huge sea ice in the northeast of Greenland cracks and Third, a Web site system at the National Satellite
thaws in short order, which is affected by the North Meteorological Center (NSMC) is available for all usAtlantic warm current.
ers worldwide to download FY-3A data and products
(online at fy3.satellite.cma.gov.cn/).
Ozone product application. Total ozone amounts
with full resolution of 50 km are calculated daily. The Forward look. The FY-3 series has two
ozone status over the Antarctic was analyzed by using phases—one of that is experimental and one of that
the retrievals from TOU. Ozone amounts started to is operational. The first two satellites (FY-3A/B) are
decrease from 28 August to 30 September 2008. It experimental satellites. The purposes of FY-3A/B are
reduced to a minimum, then increased and returned risk reduction in engineering, products development
to normal around 14 January 2009. Figure 8 shows an and validation, and utilization demonstration in
image of the deep ozone hole in Antarctic.
some areas. The second satellite, FY-3B is planned to
launch next year. There are
four satellites in phase two.
The satellite constellation
for the operational phase
(FY-3C/D/E/F) is planned
with expanded sounding
and imaging capabilities.
Two polar satellites will
be in operation: one in
morning and one in an
evening orbit; the payloads
will be different for the
morning/evening satellites. Weather purpose sensors will be onboard both
morning and afternoon
orbits while atmospheric
Fig. 6. A global land surface temperature image from MWRI data.
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components sensors will
be onboard afternoon orbits. One low-inclination
orbit satellite is planned,
mainly for precipitation
me a su re me nt (m a i n ly
radar and passive microwave measurement). Details are still in discussion.
China will continue its
effort to develop two types
[Low Earth Orbit satellite
(LEO) and Geostationary
satellite (GEO)] of meteorological and environmental
satellites to meet national
requirements and to modernize the meteorological
service of China and the
world meteorological comFig. 7. Greeland sea ice monitoring with MERSI 250-m datasets on (top left)
munity. The Chinese mete16 Jul, (top right) 23 Jul, (bottom left) 31 Jul and (bottom right) 31 Aug 2008.
orological satellite program
is one of the components of
the space-based Global Observing System (GOS) of
the World Meteorological Organization (WMO). It
is believed that the Chinese satellites not only benefit the nation of China, but they are also a valuable
contribution to the international meteorological,
hydrological, and environmental community.
ACKNOWLEDGMENTS. The authors are pleased to
acknowledge the people who have made contributions to
FY-3A and its ground segment developments. The authors
also wish to thank the three anonymous reviewers for their
valuable comments and suggestions.
REFERENCES
Ceckowski, D. H., R. P. Galvin, and M. A. Kanalos,
1995: HIRS/3-ITS predecessors and progeny. Technical Proc. of the Eighth Int. TOVS Study Conf.,
Queenstown, New Zealand, ITWG, 87–94.
Klaes, K. D., 1995: Preparations for ATOVS data processing in Europe. Technical Proc. of the Eighth Int.
TOVS Study Conf., Queenstown, New Zealand,
ITWG, 247–258.
Li, J., C.-Y. Liu, H.-L. Huang, T. J. Schmit, X. Wu, W. P.
Menzel, and J. J. Gurka, 2005: Optimal cloud-clearing
for AIRS radiances using MODIS. IEEE Trans.
Geosci. Remote Sens., 43, 1266–1278.
Robel, J., Ed., cited 2006: NOAA KLM User’s Guide with
NOAA-N and -N’ Supplement. December 2006 revision. [Available online at www.ncdc.noaa.gov/oa/.)
AMERICAN METEOROLOGICAL SOCIETY
Fig. 8. The deep ozone hole over the South Pole retrieved
from TOU. The unit of ozone is Dobson (DU).
Smith, W. L., and H. M. Woolf, 1976: The use of eigenvectors of statistical covariance matrices for interpreting satellite sounding radiometer observations.
J. Atmos. Sci., 33, 1127–1140.
Xue, J.-S., and D.-H. Cheng, 2008: Design and Application of the Weather Prediction System (GRAPES).
China Science Press, 383 pp.
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APPENDIX: SOUNDING MiSSION.
Table A1. IRAS channel characteristics.
Channel
No.
Channel
central wave
number (cm−1)
Central
wavelength
(µm)
Half-power
bandwidth
(cm−1)
Main
absorber
Max scene
temperature
(K)
NEΔN
(mW m –2 sr cm−1)
1
669
14.95
3
CO2
280
3.00
2
680
14.71
10
CO2
265
0.59
3
690
14.49
12
CO2
250
0.53
4
703
14.22
16
CO2
260
0.26
5
716
13.97
16
CO2
275
0.30
6
733
13.64
16
CO2 /H2O
290
0.31
7
749
13.35
16
CO2 /H2O
300
0.24
8
802
12.47
30
Window
330
0.14
9
900
11.11
35
Window
330
0.12
10
1030
9.71
25
O3
280
0.16
11
1345
7.45
50
H2O
330
0.07
12
1365
7.33
40
H 2O
285
0.09
13
1533
6.52
55
H2O
275
0.11
14
2,188
4.57
23
H 2O
310
0.007
15
2,210
4.52
23
N 2O
290
0.006
16
2,235
4.47
23
CO2 /N2O
280
0.006
17
2,245
4.45
23
CO2 /N2O
266
0.005
18
2,388
4.19
25
CO2
320
0.004
19
2,515
3.98
35
Window
340
0.004
20
2,660
3.76
100
Window
340
0.002
21
14,500
0.69
1,00
Window
100%A
0.055%A
22
11,299
0.885
385
Window
100%A
0.067%A
23
10,638
0.94
550
H 2O
100%A
0.060%A
24
10,638
0.94
200
H 2O
100%A
0.041%A
25
8,065
1.24
650
H 2O
100%A
0.075%A
26
6,098
1.64
450
H 2O
100%A
0.054%A
Table A2. MWTS channel characteristics.
Channel
No.
Central
frequency (GHz)
Main
absorber
Bandwidth
(MHz)
NEΔT (K)
Antenna beam
efficiency (%)
Dynamic range
(K)
1
50.30
Window
162
0.16
94.9
3 ~ 340
2
53.60
O2
356
0.15
94.8
3 ~ 340
3
54.94
O2
375
0.09
95.6
3 ~ 340
4
57.29
O2
316
0.17
94.7
3 ~ 340
1540 |
october 2009
Table A3. MWHS channel characteristics.
Channel
No.
Central
frequency (GHz)
Main
absorber
Bandwidth
(MHz)
NEΔT (K)
Antenna beam
efficiency (%)
Dynamic
range (K)
1
150(V)
Window
1001
0.9
≥96
3 ~ 340
2
150(H)
Window
987
0.71
≥96
3 ~ 340
3
180 ± 1
H 2O
481
1.01
≥98
3 ~ 340
4
180 ± 3
H 2O
1034
1.06
≥98
3 ~ 340
5
180 ± 7
H 2O
2186
1.19
≥98
3 ~ 340
APPENDIX: OZONE MISSION.
Table B1. SBUS channel characteristics.
Channel No.
Central wavelength (nm)
Bandwidth (nm)
1
252.00 ± 0.03
1.08 ~ 1.16
2
273.62 ± 0.03
1.08 ~ 1.16
3
283.10 ± 0.03
1.08 ~ 1.16
4
287.70 ± 0.03
1.08 ~ 1.16
5
292.29 ± 0.03
1.08 ~ 1.16
6
297.59 ± 0.03
1.08 ~ 1.16
7
301.97 ± 0.03
1.08 ~ 1.16
8
305.87 ± 0.03
1.08 ~ 1.16
9
312.57 ± 0.03
1.08 ~ 1.16
10
317.56 ± 0.03
1.08 ~ 1.16
11
331.26 ± 0.03
1.08 ~ 1.16
12
339.89 ± 0.03
1.08 ~ 1.16
Cloud cover radiometer
379.00 ± 1.00
3 + 0.03
Channel No.
Central wavelength (nm)
Bandwidth (nm)
1
308.68 ± 0.029
1.06 ~ 1.13
2
312.59 ± 0.029
1.06 ~ 1.13
Table B2. TOU channel characteristics.
3
317.61 ± 0.029
1.06 ~ 1.13
4
322.40 ± 0.029
1.06 ~ 1.13
5
331.31 ± 0.029
1.06 ~ 1.13
6
360.11 ± 0.029
1.06 ~ 1.13
AMERICAN METEOROLOGICAL SOCIETY
october 2009
| 1541
APPENDIX: THE EARTH RADIATION MEASUREMENT.
Table C1. ERM major characteristics.
A: Scanning mode
Channel
0.2 ~ 4.3 μm
0.2 ~ 50 μm
Field of view
2° × 2°
1.99° × 2.01°
Scan range
−51°10´ ~ 49°38´
Radiation range
0 ~ 391 W m sr
Calibration accuracy
0.82%
Sensitivity
0.15 W m sr
Stability (2 yr)
<1%
<1%
Channel
0.2 ~ >4.3 μm
0.2 ~ 50 μm
Field of view
120°
120°
Radiation range
0 ~ 370 W m−2 sr−1
0 ~ 553 W m−2 sr−1
Calibration accuracy
0.79%
0.61%
Sensitivity
0.21 W m sr
Stability (2 yr)
<1%
−2
−51°10´ ~ 49°38´
0 ~ 547 W m−2 sr−1
−1
0.65%
−2
0.27 W m−2 sr−1
−1
B: Nonscanning mode
−2
0.23 W m−2 sr−1
−1
<1%
Table C2. SIM major characteristics.
Irradiation range
100 ~ 1400 W m−2
Spectral range
0.2 ~ 50 μm
Sensitivity
0.2 W m−2
Calibration accuracy
0.5%
Stability (2 yr)
<0.02%
Quantization
16 bits
APPENDIX: IMAGING INSTRUMENTS.
Table D1. VIRR channel characteristics.
Channel No.
Wavelength (μm)
Dynamic range
Detecting sensitivity
1
0.58 ~ 0.68
ρ: 0 ~ 100%
ρ: 0.016%
2
0.84 ~ 0.88
ρ: 0 ~ 100%
ρ: 0.014%
3
3.44 ~ 3.93
190 ~ 350 K
0.25 K
1542 |
4
10.3 ~ 11.3
190 ~ 331 K
0.08 K
5
11.5 ~ 12.5
190 ~ 333 K
0.10 K
6
1.54 ~ 1.65
ρ: 0 ~ 90%
ρ: 0.013%
7
0.44 ~ 0.48
ρ: 0 ~ 50%
ρ: 0.014%
8
0.48 ~ 0.52
ρ: 0 ~ 50%
ρ: 0.016%
9
0.53 ~ 0.57
ρ: 0 ~ 50%
ρ: 0.021%
10
1.32 ~ 1.38
ρ: 0 ~ 90%
ρ: 0.042%
october 2009
Table D2. MERSI channel characteristics.
Channel
No.
Central
wavelength (µm)
Bandwidth (µm)
Subpoint
resolution (m)
NEΔT ρ (%)/K
(300 K)
Dynamic range
(ρ)/(K)
1
0.470
0.05
250
0.29
100%
2
0.550
0.05
250
0.20
100%
3
0.650
0.05
250
0.20
100%
4
0.865
0.05
250
0.23
100%
2.5
250
0.20
330k
0.02
1,000
0.045
80%
5
11.25
6
0.412
7
0.443
0.02
1,000
0.042
80%
8
0.490
0.02
1,000
0.045
80%
9
0.520
0.02
1,000
0.043
80%
10
0.565
0.02
1,000
0.046
80%
11
0.650
0.02
1,000
0.042
80%
12
0.685
0.02
1,000
0.037
80%
13
0.765
0.02
1,000
0.036
80%
14
0.865
0.02
1,000
0.037
80%
15
0.905
0.02
1,000
0.037
90%
16
0.940
0.02
1,000
0.034
90%
17
0.980
0.02
1,000
0.039
90%
18
1.030
0.02
1,000
0.047
90%
19
1.640
0.05
1,000
0.073
90%
20
2.130
0.05
1,000
0.068
90%
Table D3. MWRI channel characteristics.
Channel
No.
Central frequency
(GHz) polarization
Main
Bandwidth
absorber
(MHz)
Subpoint
resolution
(Km)
NEΔT (K)
Antenna
beam
efficiency
(%)
Dynamic
range (K)
1
10.65
V/H
Window
181.5/181
51 × 85
0.555/0.591
≥94
3 ~ 340
2
18.7
V/H
Window
213.7/220
30 × 50
0.561/0.763
≥95
3 ~ 340
3
23.8
V/H
H2O
406.3/413
27 × 45
0.50/0.538
≥95
3 ~ 340
4
36.5
V/H
Window
928/908
18 × 30
0.465/0.463
≥95
3 ~ 340
5
89
V/H
Window
2,366/2,391
9 × 15
1.069/0.893
≥96
3 ~ 340
AMERICAN METEOROLOGICAL SOCIETY
october 2009
| 1543
APPENDIX: SPACE ENVIRONMENT MONITORING UNIT.
Table E1. SEM major characteristics.
High-energy proton detector
High-energy electron detector
Channel
designation
Ep range
Channel No.
1
P1
3.0 ~ 5.0 MeV
1
E1
0.15 ~ 0.35 MeV
2
P2
5.0 ~ 10 MeV
2
E2
0.35 ~ 0.65 MeV
3
P3
10 ~ 26 MeV
3
E3
0.65 ~ 1.2 MeV
4
P4
26 ~ 41 MeV
4
E4
1.2 ~ 1.9 MeV
5
E5
1.9 ~ 5.6 MeV
Channel No.
5
P5
40 ~ 103 MeV
6
P6
103 ~ 308 MeV
Channel
designation
Table E2. SEM major characteristics (Ion detector).
He
1544 |
He: 11.6 ~ 104 MeV
Li, Be, B
Li: 24.5 ~ 215 MeV
C, N, O, F, Ne, Na
C: 61 ~ 590 MeV
Mg, Al, Si, P, S, C
Mg: 0.195 ~ 1.2 GeV
Ar, K, Ca, Sc, Ti, …
Ar: 0.29 ~ 2 GeV
Fe, …
Fe: 0.49 ~ 2.0 GeV
october 2009
Ee range