D-InSAR Research at IIT Bombay - Simulation Experiments Synchronous with ERS 1/2 Tandem Passes

During tandem period of ERS-1/2 (April June 1996), field experiments were conducted in Bhavnagar test site with Corner Reflectors (CRs) to study the sensitivity of differential SAR interferometry to estimate the movements of CRs. Initially, three images acquired on April 4, 5 and May 9, 1996 were processed to generate interferograms. Using single interferogram formed with April 4 and May 9, during which 3 CRs were moved out of 5, the movements of CRs were estimated and compared with actual measured values. The differences between estimated and measured values are 3.5 mm, 2.1 mm and 1.5 mm respectively. With the formation of Indian InSAR group through a co-ordinated program of Department of Science and Technology, we have taken up a number of projects on differential SAR interferometry. They are 1) Estimation of Koyna dam subsidence using ERS-1/2 SAR data and 2) Mapping of Chamoli 1999 Earthquake affected area. Besides the above two earthquake affected areas, we are working on some other small test sites where seismic activity is observed. We have been acquiring the data of ERS-1/2 SAR over these test sites through ERS-AO3 project sponsored by ESA and the work is in progress.