A study on different PS-like methods for subsidence in Tianjin, China

In this paper, the methods, primary PS-like method and Stanford Method for PS (StaMPS) are both studied and used to monitor the subsidence in Tianjin area. PS (Permanent Scatter) technique is possible to avoid many of the limitations of conventional DInSAR by analyzing just certain pixels which behave like point scatters and retain good correlations. Several PS-like methods have been developed and practiced by many researchers. StaMPS is a relatively new PS-like method, which uses spatial correlation of interferogram phase to find a network of stable pixels in almost all terrain without prior knowledge of temporal variations in the deformation. 17 ENVISAT SLC data for Tianjin area are used, covering from April 2003 to March 2006. The SLC scene acquired on Nov-05-2004 is chose as the master. And the results of the two methods are compared. By using the primary PS-like method and StaMPS, the subsidence field in Tianjin area has been mapped. As to PS selection, the primary PS-like method needs less input parameters and easier to understand than StaMPS. For deformation value calculation, StaMPS is good at evaluating non-linear subsidence history.