SAR Interferometry For Surface Deformation Monitoring Along Qinghai-Tibet Railway

Synthetic Aperture Radar Interferometry (InSAR) is a new technology of theEarth observation from the space, it can extract three-dimension information of theearth's surface by using phase information from SAR, and the DifferentialInterferometric Synthetic Aperture Radar (D-InSAR) based on it can monitor thesmall earth surface deformation with high accuracy (up to cm-level or even better).Comparing to the traditional remote sensing modes, InSAR possesses manyoutstanding merits including the capability to work in all-time and all weather andstrong penetrability through the ground or vegetation etc. InSAR can monitor thesmall earth surface deformation in large areas and has aboard application intopographic survey and surface displacement measurement.Through the research on space-borne InSAR system, this paper introduced thebasic theory and method of InSAR, analyzed the procedure of data processing, anddiscussed the key process in detail, such as data coregistration, phase unwrapping andbaseline evaluation and so on.This paper chosen the area of kunlun Ms 8.1 earthquake (November 14, 2001)along the Qinghai-Tibet Railway for research to detect the earth surface deformation,and the SAR data are acquired by ERS-1/2 satellites of European Space Agency.In order to monitor the earth surface deformation, we chosen the SAR databefore and after the earthquake for three-pass differential InSAR, and we also selectedthe DEM data acquired by SRTM mission for two-pass differential InSAR. Comparedwith the results, it shows that the two-pass InSAR based on high spatial resolutionexternal DEM is better than three-pass differential method in such area.