Ground subsidece monitoring along the levee of Huangpu River by multi-platform high-resolution SAR images

Persistent scatterer interferometry(PSI) technology has been applied to ground subsidence monitoring in urban area and achieved good results. However, only displacement along the direction of radar line of sight can be obtained by single platform SAR images, so the deformation results can't reflect the real settlement in the vertical direction. With the increasing of current space-borne SAR satellites, more measurements make it possible to reconstruct the vertical subsidence by the least squares solution using SAR images from different side looking angles. This paper outlines the technical process of extracting vertical deformation rate by using multi-platform PSI method. 43 km levee of Huangpu River, which passes through the Shanghai central urban area, is chosen as a test for monitoring their ground subsidence. 35 scenes of COSMO-SkyMed ascending images, 35 scenes of COSMO-SkyMed descending images and 16 scenes of TerraSAR-X images obtained from 2009 to 2010 are processed to extract ground subsidence of 1km width zone along Huangpu River. The deformation rates obtained by different platform show strong consistency and the vertical deformation rates derived by the multi-platform after comparing with existing leveling measurements show high accuracy.