Ground subsidence monitoring in western region of Shanghai Maglev by Cosmo-SkyMed ascending and descending SAR images

This paper outlines the technical processes of two InSAR techniques-IPTA (Interferometric Point Target Analysis) and TCPInSAR (Temporarily coherent point InSAR). IPTA is a kind of PSI (Permanent Scatter Interferometry) technique while TCP is a kind of multi-temporal InSAR technique. Thirty five scenes of 3m resolution COSMO-SkyMed ascending images and 35 scenes of 3m resolution COSMO-SkyMed descending images were used to estimate the average deformation rates and elevations of coherent points in the area of the western part of the maglev in Shanghai Pudong area with help from IPTA module of GAMMA software and joint TCP model. By geocoding ascending and descending deformation rates, comparison not only between the results of the two methods, but also results of two tracks are conducted. In general, these results show strong consistency, all of them show two large subsidence areas, one of which located in the junction of Maglev line and the Outer Ring Road, another in the zone surrounded by Shanghai South Highway, Metro Line 14 and Line 16.The Maglev is stable as a whole. Further analysis has been conducted on the profiles of these two areas.