The impact of second generation SAR The impact of second generation SAR sensors on the deformation time series sensors on the deformation time series

analysis via DInSAR techniques: analysis via DInSAR techniques: The COSMOThe COSMO--SkyMedSkyMed study casestudy 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

ERS1ERS1

ERS2ERS2

RADARSATRADARSAT--11

ENVISATENVISAT

2010201019921992 19951995 2001200119971997 20022002

JJ--ERS1ERS1

19981998

First Generation

20072007 2013201320062006

Secondgeneration

RADARSATRADARSAT--22

TERRASARTERRASAR--XX

COSMO/SKYMEDCOSMO/SKYMED

SENTINELSENTINEL--11

ALOSALOS

ALOSALOS--22

Most of our DInSAR knowledge comes from the exploitation of the large data archive acquired by ESA (first generation) satellites ERS-1, ERS-2 and ENVISAT

Satellite SAR System Scenario

SAR systems: from first to second generation

ERS-ENVISAT: C-Band

Spatial Resolution: 5x20 m

Revisit Time:

35 days

Archive:

06/1992-10/2010

130 acquisitions

RADARSAT-1: C-Band

Spatial Resolution: 5x7 m

Revisit Time:

24 days

Archive:

03/2003-12/2007

47 acquisitions

Cosmo-SkyMED: X-Band

Spatial Resolution: 3x3 m

Revisit Time: 8 days

Archive:

07/2009-10/2010

81 acquisitions

ERS-ENVISAT: 130 images in about 20 years COSMO-SkyMed: 81 images in 1.5 years !!!

Napoli Bay area: ERS-ENVISAT results

Campi FlegreiVomero Vesuvio

A total of 130 ERS-1/2 and ENVISAT images

ascending orbits (1993 – Oct 2010)

Mea

nve

loci

ty[c

m/y

r]

> 1,5

<-1.5

COSMO-SkyMed vs. ERS/ENVISAT: Campi Flegrei

Mea

nve

loci

ty[c

m/y

r]

> 2

<-2

COSMO-SkyMed vs. ERS/ENVISAT: Campi Flegrei

Mea

nve

loci

ty[c

m/y

r]

> 1.5

<-1.5

COSMO-SkyMed vs. ERS/ENVISAT: Campi Flegrei

COSMO-SkyMed vs. ERS/ENVISAT: Campi Flegrei

Mea

nve

loci

ty[c

m/y

r]

> 2

<-2

Mea

nve

loci

ty[c

m/y

r]

> 1.5

<-1.5

COSMO-SkyMed vs. ERS/ENVISAT: Vesuvius

Mea

nve

loci

ty[c

m/y

r]

> 2

<-2

COSMO-SkyMed vs. ERS/ENVISAT: Vesuvius

COSMOSkyMed vs. ERS/ENVISAT

COSMO-SkyMed ERS/ENVISAT

Revisit time: 8 days

Time span: Jul 2009 – Nov 2010

X Band (

= 3.1 cm)

Resolution: 30 x 30 m

Revisit time: 35 days

Time span: 1992 – Oct 2010

C Band (

= 5.6 cm)

Resolution: 90 x 90 m

ERS/ENVISAT

ERS/ENV: ~23 deg

35 days

COSMO-SkyMed

CSK: ~ 44 deg8 days

COSMO-SkyMed vs. ERS/ENVISAT Campi Flegrei

ERS/ENVISAT

Near GPS station: ACAE

ERS/ENV: ~23 deg

35 days

COSMO-SkyMed

CSK: ~ 44 deg8 days

COSMO-SkyMed vs. ERS/ENVISAT Campi Flegrei

ERS/ENVISAT

Near GPS station: ACAE

cm

Full resolution ENVISAT results

cm

Mea

nve

loci

ty[c

m/y

r]

> 1.5

< - 1.5

Full resolution COSMO-SkyMed results

81 ascending CSK (Strip mode) images (July 2009 - November 2010)

ENVISAT vs RADARSAT-1 vs COSMO-SkyMed

ENVISATtime: 03/2003 -12/2007

39 imagesresolution: 5x20 m

RADARSAT-1time: 03/2003 - 12/2007

47 imagesresolution: 5x7 m

COSMO-SkyMedtime: 07/2009 -10/2010

81 imagesresolution: 3x3 m

Mea

nve

loci

ty

> 0.5

< - 0.5

cm/y

ear

Mea

nve

loci

ty> 0.5

< - 0.5

cm/y

ear

Mea

nve

loci

ty

> 0.75

< - 0.75

cm/y

ear

Mea

nve

loci

ty[c

m/y

r]

> 1.5

< - 1.5

Napoli Bay area: COSMO-SkyMed

results

0.7 cm/year

1.5 cm/year

Mea

nve

loci

ty[c

m/y

r]

> 1.5

< - 1.5

Napoli Bay area: COSMO-SkyMed results1.3 cm/year

1.6 cm/year

< < --22 > 2> 2cm/cm/yearyearMean deformation velocityMean deformation velocity DescendingDescending

125 Descending and 147 Ascending orbit SAR data (1992 – 2010)

Mt. Etna: ERSMt. Etna: ERS--ENVISATENVISAT

AscendingAscending

ENVENVΔΔ ERSERS

Eruption

Eruption

A very complex displacement pattern over about 20 years of acquisitions!

Mt. Etna: ERSMt. Etna: ERS--ENVISATENVISAT

AscendingAscending

< < --22 > 2> 2cm/cm/yearyearMean deformation velocityMean deformation velocity

COSMO-SkyMed Results: EtnaM

ean

velo

city

[cm

/yr]

> 5

<-5

COSMO-SkyMed: 8 days

ENVISAT: 35 days Descending Orbits

Time Interval: Jul 2009 – Dec 2010

86 acquisitions

276 Interferograms

Ground Resolution: ~ 30 meters

Look Angle: 49 deg

COSMO-SkyMed Results: EtnaM

ean

velo

city

[cm

/yr]

> 5

<-5

Pernicana Fault

Descending Orbits

Time Interval: Jul 2009 – Dec 2010

86 acquisitions

276 Interferograms

Ground Resolution: ~ 30 meters

Look Angle: 49 deg

Range

Azim

uth

Possible Atmospheric

fringes

30/03/2010 - 07/04/2010 spatial baseline: 133 m

COSMO-SkyMed vs. ENVISAT: EtnaM

ean

velo

city

[cm

/yr]

> 1.5

<-1.5

COSMO-SkyMed vs. ENVISAT: EtnaM

ean

velo

city

[cm

/yr]

> 5

<-5

COSMO-SkyMed vs. ENVISAT: Etna

COSMO-SkyMed ENVISAT

Revisit Time: 8 days

Time span: Jul 2009 – Dec 2010

X-Band (

= 3.1 cm)

Resolution: 25 x 25 m

Revisit Time: 35 days

Time span: 1992 – 2010

C-Band (

= 5.6 cm)

Resolution: 90 x 90 m

COSMO-SkyMed vs. ENVISAT: Etna

COSMO-SkyMed ENVISAT

Revisit Time: 8 days

Time span: Jul 2009 – Dec 2010

X-Band (

= 3.1 cm)

Resolution: 25 x 25 m

Revisit Time: 35 days

Time span: 1992 – 2010

C-Band (

= 5.6 cm)

Resolution: 90 x 90 m

COSMO-SkyMed vs. ENVISAT: Etna

COSMO-SkyMed ENVISAT

Revisit Time: 8 days

Time span: Jul 2009 – Dec 2010

X-Band (

= 3.1 cm)

Resolution: 25 x 25 m

Revisit Time: 35 days

Time span: 1992 – 2010

C-Band (

= 5.6 cm)

Resolution: 90 x 90 m

COSMO-SkyMed vs. ENVISAT: Etna

COSMO-SkyMed

ENVISAT

Look Angle ~ 49 deg

Look Angle ~ 23 deg

TerraSAR-X: Mt. EtnaDescending Orbits

Time Interval: Sep 2008 – Dec 2009

27 acquisitions (cfr. 86 COSMO)

76 Interferograms

Ground Resolution: ~ 30 meters

Look Angle: 42.9 deg

< -6 > 6cm/year

Mean deformation velocity

ENVISAT90x90 m

ENVISAT vs. TerraSAR-X: Spatial Coverage

TerraSAR-X30x30 m

ENVISAT vs. TerraSAR-X: Spatial Coverage

ENVISAT vs. TerraSAR-X : Time Sampling

ENVISAT: 35 days

TerraSAR-X: 11 days

COSMO-SkyMed – TerraSAR-X vs. ENVISAT: Mt. Etna

COSMO-SkyMedCOSMO-SkyMed - TerraSARX

TSX: ~ 43 deg

CSK: ~ 49 deg

ENVISATENV: ~23 deg

CSK: 8 days

TSX: 11 days

ENV: 35 days

ConclusionsSecond 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.