1）College of Geology Engineering and Geomatics，Chang’an University，Xi’an 710054 2）Key Laboratory of Western China’s Mineral Resources and Geological Engineering，Ministry of Education，Xi’an 710054）
Abstract：The deformation data from the InSAR processing are always massive and always include some errors due to decorrelation，which cannot be detected from image expressing.However，compared with the conventional surveying data or inversion analysis，it should be better eliminated and greatly compressed when discrete feature points are extracted or with a contour line from InSAR.On the basis of the quadtree compressing，Kriging interpolation and Lowpass filter，a flowchart of the contour mapping is proposed for the InSAR deformation data.Finally the method is evaluated through a case study of the twoperiod ground subsidence around Xi’an City in 1996.
