Using InSAR Technique For Monitoring Urban Ground Subsidence

Differential Synthetic Aperture Radar interferometry(D-InSAR) is a newly deceloped technique for monitoring large-scale ground deformation with some prominent advantages such as high accuracy and pantoscopic view. Since 1990s, D-InSAR technology has been popular in geoscience field. Many breakthroughs have been achieved, such as the monitoring of hundreds of earthquake throughout the world, of pre-co-and post-eruption of volcanoes, and the measuring of flow speed of ice sheets in Antarctic, of land sliding, subsidence of mine area and other man-made disasters.However, D- InSAR technique is still under development. There are still some bottlenecks that need to be solved, such as time decorrelation, baseline decorrelation, atmospheric delay, phase unwrapping and so on. Additionally, there have no enough data and the InSAR processing sofewar, it restrict the application of the InSAR.In this paper, at first we give the basic theory and algorithm-processing flow chart of InSAR and D-InSAR, Various method that the InSAR technique monitor the deformation of the earth has been introduced . Another, The SLC data format of satellite SAR and the corresponding parameters on interferometry have been thoroughly studied in this paper.Based on open-source software, a basic framework of InSAR processing has been put forward and functional software tools for InSAR processing in Linux system have been developed. especially, we use a new modified Goldstein filtering algorithm in this InSAR processing sofeware.Finally, the ground subsidence of xian and Shanghai has been successfully detected using D-InSAR technique in our InSAR processing sofeware . Compared with the ground-based measurements, the results are viable and reliable. It also proved the D-InSAR technique has a good prospect in urban land subsidence monitoring field in the future.