Surface Subsidence Monitoring with Coherent Point Target SAR Ineterferometry

In this paper, an improved approach for surface subsidence monitoring with SAR interferometry by using coherent point target is presented. A joint criterion of amplitude dispersion index and high spectral correlation criterion are proposed for coherent point target identification, which enable a flexible target selection in case of small or large volume of SAR data. Further more, in order to avid the decorelation caused by long temporal or spatial baseline, interferogram stack are generated from the combination of those images with a small baseline. For subsidence rate calculation, a spatial and temporal regression is exploited to unwrap the differential phase of each coherent point target and a linear model is adopted for the estimation of deformation parameters. Case studies in two different test sites demonstrate the advantage and limitations of the algorithm.