Subsidence Measurement with Ps-insar Techniques in Shanghai Urban

Spaceborne SAR Differential interferometry (DInSAR) has been used to monitor some geological disasters such as ground subsidence. This paper applies two Permanent Scatterer InSAR(PS-InSAR) techniques to measure long-term and short-term subsidence in urban area of Shanghai urban. A great number of archieved ERS data are utilized to measure long-term subsidence during 1993-2000 year. A small set of ASAR data are utilized to measure short-term subsidence during 2003-2005 year. The subsidence measurement results are examined with simultaneous leveling during the two periods, and comparison result shows a good agreement. Furthermore, the causes of subsidence are qualitatively analyzed in the main subsidence regions of Shanghai urban, and the variation of subsidence in two different periods can be detected according to the obtained subsidence measurement results.