ALOS PALSAR differential interferometry for mapping co-seismicdeformation of the 2008 Wenchuan earthquake, China

摘要

Differential interferometric synthetic aperture radar (DInSAR) technique has been widely accepted as a powerful tool to map surface deformation. To quantitatively evaluate the surface displacement caused by Wenchuan Earthquake on 12 May 2008 in Sichuan Province, China, a series of interferograms were generated from 25 ALOS/PALSAR image pairs, and the surface displacement was then mapped. According to the wrapped differential interferogram, the main rupture fault was plotted with an orientation of North-East 47° and a spanning length of approximately 230 km. The serious affected region with area of 5,000 km~2 and the affected region with area of 250,000 km~2 were also mapped. Along the radar look of sight (LOS), it is estimated that the ground surface displaced approximated a maximum of 57 cm and 119 cm away from and towards the satellite respectively, i.e. the vertical displacement was a maximum of 73 cm and 150 cm down lift and uplift respectively. The capability of DInSAR technique and ALOS PALSAR data for co-seismic deformation mapping has been demonstrated and proved to be useful in the surface deformation applications. In addition, some limitations were discussed including the topographic, atmospheric, and orbital errors.