Sentinel-1 tops data for digital elevation model generation and estimation of glacier velocity using INSAR technique
Student name: Mr Prashant
Guide: Dr Vinay Shankar Prasad Sinha
Year of completion: 2017
Host Organisation: Polar Remote Sensing Division, National Centre for Antarctic and Ocean Research (NCAOR)
Supervisor (Host Organisation): Mr Shridhar D. Jawak and Dr Alvarinho J. Luis
Abstract: The Synthetic Aperture Radar Interferometry (InSAR) is a dominant method for monitoring earth
surface mainly to measure its topography and deformation. It is a widely used technique in
multidisciplinary applications. By using two SAR images we can generate interferogram that are
having phase and amplitude information, the phase information from two and more interferogram
further help to extract information about height and displacement of the surface. In present study,
digital elevation model generated as well as velocity is estimation for Polar record glacier and
Potsdam glacier, east Antarctica using Sentinel-1 SLC of Interferometric Wide mode data. With
the help of differential SAR interferometry method the DEM is generated using two interferogram
images of different dates of more than 140 meter of baseline gap and 6-12 days temporal
difference. This study generated DEM with approx. ± 11 m of vertical accuracy for polar record
glacier whereas ± 6 m for Potsdam glacier. The generated DEM elevations have been validated
with ground collected DGPS point data from field survey. For velocity estimation, Persistent
Scatterer interferometry (PS-InSAR) method has been applied. This method uses only time
coherent of permanent pixel of master images and correlates to same pixel of the slave image to
get displacement. Current C-band sensor of European Space Agency, Sentinel-1A and 1B data are
freely available to exploit it for results. This study estimated about annual velocity of ≈700m in
lower part whereas the upper inland area giving ≈200m for Polar Record glacier. For Potsdam
glacier, estimated annual average velocity 36m/annual, but the velocity varies from higher
elevation to lower elevation. . In this study, for ground verification of digital elevation model’s we
have 10-20 DGPS point but for precise level of accuracy, it must be more and more. For glacier
velocity, increase in images number will increase accuracy.
Keywords: InSAR, PS Interferometry, DEM, Glacier Velocity, Sentinel-1
