Extract and Analysis Surface Deformation Caused by Wenchuan Mw7.9 Earthquake from InSAR Data

On 12 May 2008,a Mw 7.9 Wenchuan Earthquake occurred in Sichuan Province,China,which is located in Longmenshan mountain area with bald relief and dense vegetation.The smaller wavelength(C-band) system can not provide high quality interferograms.In order to map co-seismic deformation in earthquake region,the SAR data collected by L band ALOS/PALSAR sensor of JAXA are used in the study,including before and after the quake from six paths.A two-pass differential InSAR technology and external DEM acquired by SRTM mission are employed in GAMMA software to generate the co-seismic deformation field.GPS observation results of co-seismic deformation surveyed by Chinese national large scientific project-Crustal Movement Observation Network of China(CMONC) project team are used to evaluate the InSAR observations.The result shows that there is a high consistent between GPS and InSAR observations.And accuracy of line of sight surface displacement derived from traditional InSAR technique can achieve cm-level.