Multi-platform persistent scatterer SAR interferometry time series analyzing

Exploration on persistent scatterer radar interferometry (PSI) and its applications to regional deformation monitoring has become one of the hot research topics in the radar remote sensing community. PSI analysis with time series of SAR images collected by a single side-looking mode from a single satellite platform can only reveal its own ground deformation along the direction of radar line of sight (LOS). This paper proposes the modeling and algorithm for extracting vertical deformation rate field (DRF) accurately using a multi-platform PSI (MPSI) method. Its basic strategy includes two parts. Above all, the SAR images collected by each single platform are first used to estimate LOS DRF by PSI analysis. Then, imaging geometric space relationship of different satellite platforms has been modeled. Finally, all the DRFs obtained from different platforms are combined to resolve vertical DRF by the least squares solution. For validation purpose, the northwestern part of Tianjin (China) is selected as the testing area, and 39 TerraSAR-X images, 23 ENVISAT ASAR and 16 ALOS PALSAR images collected over this area between 2007 and 2010 are used to estimate the vertical DRF. The comparison with the ground-based leveling results indicates that the vertical deformation rates derived by the combined solution can reach up to a millimeter accuracy level.