SURFACE SUBSIDENCE MONITORING AND ANALYZING IN BEIJING BASED ON INTERFEROMETRIC POINT TARGET ANALYSIS

Abstract. Temporal and geometrical decorrelation often prevents SAR interferometry from being an operational tool for surface deformation monitoring. Moreover, atmospheric disturbances can strongly compromise the accuracy of the results. In order to solve the above problem. In this paper, Interferometric Point Target Analysis (IPTA) technology was used to obtain surface deformation information with an area of 700 km² in Beijing. In the experiment, 20 TerraSAR-X images from October 2014 to June 2016 were selected to monitor the surface subsidence in Beijing and higher resolution and higher accuracy WorldDEM obtained by DLR was used to simulated terrain phase, so as to register the high-resolution TerraSAR-X image. The final results show the surface subsidence tendency of Beijing urban from October 2014 to June 2016: in the center of monitor area surface tends to be stable within approximately subsidence rate of 3 mm/a. In the east of monitor, the area of Chaoyang and Tongzhou, there are obvious subsidence phenomenon。This subsidence is affected by groundwater exploitation, flake subsidence it had an tendency of expanding to the east and south, and the maximum annual subsidence is more than 76 mm/year. The results of this monitoring are basically consistent with the published data of surface subsidence in Beijing.