SAR interferometry for DEM generation and movemnet of Indian glaciers

Two famous glaciers viz. Gangotri and Siachen were studied for DEM generation and movement using ERS-1&2 tandem data. While surrounding areas along the glaciers showed more decorrelation, glacier area showed a very good correlation between two image acquisitions. Contours obtained using ERS-1&2 SAR tandem data closely match with topographic maps of the area. Two-pass differential method was used along with SRTM DEM to study the movement of the glaciers. According to the differential interferogram over Gangotri, 3 fringes equivalent to 8.4 cm displacement in the radar look direction were observed, whereas for Siachen the fringes were about 8 which is equivalent to 22 cm. The estimated DEMs and movements are to be verified using GPS measurements