The Study Of Deformation Monitoring Based On SAR Interferometry

Deformation monitoring is widely used in the safety monitoring of the varioustypes of geological disasters and large buildings. During the various methods ofdeformation monitoring, the Radar Interferometry has a unique advantage of24-hourreal-time remote monitoring. There are three modes of Radar Interferometry System:Spaceborne, Airborne and Ground-based. The Spaceborne mode and the Ground-basedmode have been discussed in this dissertation. For the difference of the deformationmeasurement principle and data processing between the Spaceborne and Ground-basedInSAR, and for the data processing to improve measurement accuracy, the followingwork has been done.Firstly, this dissertation analyzed the spcaborne InSAR measurement principlecombined with the observation model, and analyzed the composition of interferometricphase and the data processing steps for acquiring DEM. ENVI+SARscape Softwarewere used to do Spaceborne-InSAR experiment. Stared form baseline estimation, thenregistration, interferogram generation, flat-earth removal, adaptive filtering, phaseunwrapping, track refining, elevation inversion, and ultimately the Spaceborne-InSARexperiment has been done to obtain a DEM, with15m accuracy.Secondly, this dissertation analyzed the principle of spcaborne DInSAR fordeformation measurement, and the composition of differential interferometric phase andthe data processing steps for deformation measurement. ENVI+SARscape Softwarewere used to do Spaceborne DInSAR experiment to measure the deformation value.Using Two-Pass method to deal with the DEM and two SLC images, the DInSAR dataprocessing starts from baseline estimation, then registration, interferogram generation,flat-earth removal, adaptive filtering, phase unwrapping, track refining, ultimatelyobtain the differential interferogram, from which we can obtain the deformationinformation with centimeter accuracy.Thirdly, this dissertation built a model of Ground-based InSAR for deformationmeasurement, derive the principle and data proceesing steps of the Ground-basedInSAR. Due to the experimental conditions, the SLCs before and after the deformation were generated by MATLAB. According to the SFCW singal principle and the azimuthsynthetic aperture principle, simulate the echo signal and obtain the SLCs byGroud-based SAR imaging. In the subsequent experiment of Ground-based InSAR, thekey step is phase unwrapping. Using the Branch-cut method as well as theQuality-guide algorithm of unwrapping, we can see the Quality-guide algorithm ismuch more simple and effective. From the unwrapped interferogram, we obtain thelocation and the value of the deformation, with centimeter accuracy.