A comprehensive interferometric process for monitoring land deformation using ASAR and PALSAR satellite interferometric data

This study was conducted to apply the enhanced differential interferometric process to interferometric data obtained from C-band Advanced Synthetic Aperture Radar (ASAR) and Phased Array type L-Band Synthetic Aperture Radar (PALSAR) systems, in the Marand plain, Iran. In advance, the capability of each sensor was examined with regard to the signal coherency for sensor-target interactions, which emphasized on the terrific excellency of PALSAR (L-band) to ASAR (C-band) measurements in study area. In the interferometric process, in addition to resolving the topography and baseline related errors (which is conventional in the standard D-InSAR process), subtle quantitative methods were outlined to minimize the secondary, but momentous errors (i.e., orbital and atmospheric) from differential phases. Subsequently, based on the outlined process, the mean deformation as well as three-dimensional displacement maps (using ascending and descending modes) were generated. The deformation maps significantly indicated the downward motion of the surface with the maximum rate of -0.5 millimetre per day for the period, i.e., from 2004 to 2010, with relative dominance in eastern and central to northern parts of the Marand plain. Finally, the results were validated and the source of deformation was inspected using field data such as seismic history; changes in piezometric levels and cross-checking the results from radar measurements itself.