ers-envisat tandem cross-interferometry...

ERS-2 / ASAR CInSAR campaigns

www.sarmap.ch 3 / 12 / 2009

ERSERS--Envisat Tandem CrossEnvisat Tandem Cross--Interferometry Interferometry Campaigns: first results of CInSAR Campaigns: first results of CInSAR

processing and studies over extended areasprocessing and studies over extended areas

P. Pasquali(1), M. Barbieri(1), A. Cantone(1),

P. Riccardi(1) and M. Engdahl(2)

(1) sarmap s.a., Cascine di Barico, 6989 Purasca, Switzerland

(2) ESA ESRIN, , Frascati, Italy



ERSERS--ASAR CinSAR InterferometryASAR CinSAR Interferometry

Very large baseline (~2km) to compensate the carrier frequencies difference

-> Very sensitive to height (2pi ~5m)-> Coherence maintained for little slopes-> Volume decorrelation is significant

Doppler Centroid difference shall not be large

Short acquisition interval (~28 minutes)



First CInSAR campaign: September 25th 2007 – February 12th 2008

Valid pairs: 1368

Not valid pairs: 1211 (469 bad baseline, 950 too large DC difference)



Second CInSAR campaign: November 18th 2008 – April 7th 2009

Valid pairs: 3193

Not valid pairs: 2628 (721 bad baseline, 2133 too large DC difference)



Coherence statisticsCoherence statistics

- Water areas- Land areas with favourable slope- Land areas with non favourable slope



www.cinsar.info/Joomlawww.cinsar.info/Joomla



Fast displacement of iceFast displacement of ice



GenerationGeneration of of veryvery highhigh resolutionresolution DEMsDEMs

ERS-2 / ASAR DEM Google EarthERS-2 / ASAR phase

Northern Siberia. Every 2

colour cycle corresponds to ~5m elevation difference.The whole height variation is less than 20m in the whole area.



NorthernNorthern SiberiaSiberia coherencecoherence

Potential for filling in / extending SRTM



NorthernNorthern SiberiaSiberia



NorthernNorthern AlaskaAlaska



Atmospheric Atmospheric artefactsartefacts



Volume Volume decorrelationdecorrelation



Volume Volume decorrelationdecorrelation

ERS-1/2 Tandem phase1 day separation

180m normal baseline

ERS-2 / ASAR phase28minutes separation

2100m normal baseline

Google Earth



ConclusionsConclusions

Not soo soon, please!We are enjoying it soo much….

ers-envisat tandem cross-interferometry...

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