The impact of second generation SAR sensors

The impact of second generation SAR sensors

The impact of second generation SAR
sensors on the deformation time series
analysis via DInSAR techniques:
The COSMO-SkyMed study case
Manuela Bonano, Francesco Casu, Riccardo Lanari, Michele
Manunta, Luca Paglia, Giuseppe Solaro, Eugenio Sansosti
Istituto per il Rilevamento Elettromagnetico dell’Ambiente, IREA
National Research Council of Italy (CNR)
Via Diocleziano 328, 80124 Napoli, Italia
e-mail: eugenio.sansosti@cnr.it
First Generation
1992
1995
1997 1998
Satellite SAR System Scenario
2001
2002
2006
2007
2010
2013
ERS1
J-ERS1
ERS2
RADARSATRADARSAT-2
RADARSATRADARSAT-1
ENVISAT
ALOS
COSMO/SKYMED
Most of our DInSAR knowledge
-X
TERRASAR
comes from theTERRASARexploitation
of the
large data archive acquired by
ESA
SENTINEL-1
SENTINEL
(first generation) satellites ERS-1,
ALOSALOS-2
ERS-2 and ENVISAT Second
generation
SAR systems: from first to second generation
ERS-ENVISAT: 130 images in about 20 years
COSMO-SkyMed: 81 images in 1.5 years !!!
ERS-ENVISAT: C-Band
RADARSAT-1: C-Band
Cosmo-SkyMED: X-Band
Spatial Resolution: 5x20 m
Spatial Resolution: 5x7 m
Spatial Resolution: 3x3 m
Revisit Time: 35 days
Revisit Time: 24 days
Revisit Time: 8 days
Archive: 06/1992-10/2010
Archive: 03/2003-12/2007
Archive: 07/2009-10/2010
130 acquisitions
47 acquisitions
81 acquisitions
Napoli Bay area: ERS-ENVISAT results
Vomero
Vesuvio
Campi Flegrei
A total of 130 ERS-1/2 and ENVISAT images
ascending orbits (1993 – Oct 2010)
COSMO-SkyMed vs. ERS/ENVISAT:
Campi Flegrei
Mean velocity [cm/yr]
> 1,5
<-1.5
COSMO-SkyMed vs. ERS/ENVISAT:
Campi Flegrei
Mean velocity [cm/yr]
>2
<-2
COSMO-SkyMed vs. ERS/ENVISAT:
Campi Flegrei
Mean velocity [cm/yr]
> 1.5
<-1.5
COSMO-SkyMed vs. ERS/ENVISAT:
Campi Flegrei
Mean velocity [cm/yr]
>2
<-2
COSMO-SkyMed vs. ERS/ENVISAT:
Vesuvius
Mean velocity [cm/yr]
> 1.5
<-1.5
COSMO-SkyMed vs. ERS/ENVISAT:
Vesuvius
Mean velocity [cm/yr]
>2
<-2
COSMOSkyMed vs. ERS/ENVISAT
COSMO-SkyMed
ERS/ENVISAT
Revisit time: 8 days
Revisit time: 35 days
Time span: Jul 2009 – Nov 2010
Time span: 1992 – Oct 2010
X Band ( = 3.1 cm)
C Band ( = 5.6 cm)
Resolution: 30 x 30 m
Resolution: 90 x 90 m
COSMO-SkyMed vs. ERS/ENVISAT
Campi Flegrei
Near GPS station: ACAE
ERS/ENVISAT
ERS/ENV:
~23 deg
ERS/ENVISAT
COSMO-SkyMed
days
835days
CSK: ~ 44 deg
COSMO-SkyMed vs. ERS/ENVISAT
Campi Flegrei
Near GPS station: ACAE
ERS/ENV:
~23 deg
ERS/ENVISAT
COSMO-SkyMed
days
835days
CSK: ~ 44 deg
Full resolution ENVISAT results
cm
cm
Full resolution COSMO-SkyMed results
Mean velocity [cm/yr]
> 1.5
< - 1.5
81 ascending CSK (Strip mode) images (July 2009 - November 2010)
ENVISAT vs RADARSAT-1 vs COSMO-SkyMed
cm/year
Mean velocity
> 0.5
ENVISAT
time: 03/2003 -12/2007
39 images
resolution: 5x20 m
< - 0.5
cm/year
Mean velocity
> 0.5
RADARSAT-1
time: 03/2003 - 12/2007
47 images
resolution: 5x7 m
< - 0.5
cm/year
Mean velocity
> 0.75
< - 0.75
COSMO-SkyMed
time: 07/2009 -10/2010
81 images
resolution: 3x3 m
Napoli Bay area:
COSMO-SkyMed
results
0.7 cm/year
Mean velocity [cm/yr]
> 1.5
< - 1.5
1.5 cm/year
Napoli Bay area: COSMO-SkyMed results
1.3 cm/year
Mean velocity [cm/yr]
> 1.5
< - 1.5
1.6 cm/year
Mt. Etna: ERS-ENVISAT
125 Descending and 147 Ascending
orbit SAR data (1992 – 2010)
Ascending
Descending
Mean deformation velocity
< -2
cm/year
>2
Mt. Etna: ERS-ENVISAT
Eruption
Eruption
A very complex displacement pattern
over about 20 years of acquisitions!
Ascending
Mean deformation velocity
< -2
cm/year
>2
Δ ERS Δ ENV
COSMO-SkyMed Results: Etna
ENVISAT: 35 days
Descending Orbits
>5
Mean velocity [cm/yr]
Time Interval:
Jul 2009 – Dec 2010
86 acquisitions
276 Interferograms
COSMO-SkyMed: 8 days
<-5
Ground Resolution:
~ 30 meters
Look Angle: 49 deg
COSMO-SkyMed Results: Etna
Pernicana Fault
Descending Orbits
>5
Mean velocity [cm/yr]
Time Interval:
Jul 2009 – Dec 2010
86 acquisitions
276 Interferograms
<-5
Ground Resolution:
~ 30 meters
Look Angle: 49 deg
Range
Azimuth
30/03/2010 - 07/04/2010
spatial baseline: 133 m
Possible
Atmospheric
fringes
COSMO-SkyMed vs. ENVISAT: Etna
Mean velocity [cm/yr]
> 1.5
<-1.5
COSMO-SkyMed vs. ENVISAT: Etna
Mean velocity [cm/yr]
>5
<-5
COSMO-SkyMed vs. ENVISAT: Etna
COSMO-SkyMed
ENVISAT
Revisit Time: 8 days
Revisit Time: 35 days
Time span: Jul 2009 – Dec 2010
Time span: 1992 – 2010
X-Band ( = 3.1 cm)
C-Band ( = 5.6 cm)
Resolution: 25 x 25 m
Resolution: 90 x 90 m
COSMO-SkyMed vs. ENVISAT: Etna
COSMO-SkyMed
ENVISAT
Revisit Time: 8 days
Revisit Time: 35 days
Time span: Jul 2009 – Dec 2010
Time span: 1992 – 2010
X-Band ( = 3.1 cm)
C-Band ( = 5.6 cm)
Resolution: 25 x 25 m
Resolution: 90 x 90 m
COSMO-SkyMed vs. ENVISAT: Etna
COSMO-SkyMed
ENVISAT
Revisit Time: 8 days
Revisit Time: 35 days
Time span: Jul 2009 – Dec 2010
Time span: 1992 – 2010
X-Band ( = 3.1 cm)
C-Band ( = 5.6 cm)
Resolution: 25 x 25 m
Resolution: 90 x 90 m
COSMO-SkyMed vs. ENVISAT: Etna
COSMO-SkyMed
Look Angle ~ 49 deg
ENVISAT
Look Angle ~ 23 deg
TerraSAR-X: Mt. Etna
Descending Orbits
Time Interval:
Sep 2008 – Dec 2009
27 acquisitions (cfr. 86 COSMO)
76 Interferograms
Ground Resolution: ~ 30 meters
Look Angle: 42.9 deg
Mean deformation velocity
< -6
>6
cm/year
ENVISAT vs. TerraSAR-X: Spatial Coverage
ENVISAT
90x90 m
ENVISAT vs. TerraSAR-X: Spatial Coverage
TerraSAR-X
30x30 m
ENVISAT vs. TerraSAR-X : Time Sampling
ENVISAT: 35 days
TerraSAR-X: 11 days
COSMO-SkyMed – TerraSAR-X vs. ENVISAT: Mt. Etna
CSK: 8 days
COSMO-SkyMed - TerraSARX
CSK: ~ 49 deg
TSX: ~ 43 deg
TSX: 11 days
ENVISAT
ENV: 35 days
ENV: ~23 deg
Conclusions
Second Generation Satellite data
• are suitable for Advanced DInSAR techniques (time series),
with great potential in terms of improved temporal sampling
and spatial resolution
• dramatically extend performances: “moving” from
deformation analysis to deformation monitoring
• allow detection of fast movement (such as earthquakes)
• allow measurements of intra-building displacements
Issues
• Accuracy should be assessed
• Atmospheric artifacts correction
• Processing of a huge amount of data needs high
computing and storage capabilities!!!
Acknowledgements
Thanks to:
• Italian Space Agency (ASI) for COSMO-SkyMed
data; they were acquired and processed within the
Volcanic System Risk (SRV) Pilot Project.
• ESA for ERS-1/2 and ENVISAT collected over
many years via several CAT-1 projects and
contributed to the Geo Supersites initiative.
• DLR for TerraSAR-X data on Etna obtained
through the Geo Supersites initiative.