Persistence scatterer interferometry for surface movement mapping over Himalayan region

ENVISAT ASAR images acquired during 2003 to 2007 were processed using PSInSAR and SBAS methods for surface movement studies due to landslides. The average velocity of the movement obtained using PSInSAR method is from −12.72 to 14.59 mm/year for ascending pass and −15.8 to 17.20 mm/year for descending pass. Using SBAS method, the mean velocity obtained is −38.7 to 37.9 m/year in ascending and −6.3 to 16.4 mm/year in descending pass. The number of PS points found on SAR images with SBAS method are very much less than that of observed with PSInSAR. By overlaying the PS points on DEM, we found that highest displacement was observed at high slope areas. An analysis of the landslides using PSInSAR method along ascending and descending line of sight yielded maximum movement across the glacier area. For accurate use of PSInSAR for landslide monitoring, more images are needed.