Abstract: INSAR (Interferometric Synthetic Aperture Radar) is a new technique developed in the last decade. It has a non-replaceable application potential in observing vertical deformation of ground surface. It would provide entirely new means and method for monitoring the dynamic field of earthquake. In the SAR images acquired, not only the intensity information but also the phase information of surface features has been recorded, which is an advantage unparalleled by optical remote sensing. Using phase information, the INSAR technique may provide digital elevation model and information on surface deformation. The algorithms of INSAR and D-INSAR (Differential INSAR) are introduced in this paper in details. This new technique has been applied to the study of Mani, Tibet earthquake of Nov. 11, 1997. For detecting the characteristics of deformation produced by Mani earthquake, we have collected three ERS-1/2 SAR images of Mani area, two of which (May 20,1996 and May 21,1996) are tandem mode data (1 day repeat) before Mani M_S 7.9 earthquake in 1997, one of which (April 21,1998) after the earthquake. We used three pass interferometric mode to process the images. First, we used May 20 and May 21,1996 images by making interferometric processing, and extracting the DEM of the studied area. Then, we used May 21 ,1996 and April 21,1998 images by making differential interferometric processing, and removing the effect of terrain obtained from DEM. At last, we detected co-seismic surface displacement of Mani earthquake by D-INSAR technique. The results show that the surface deformation caused by Mani earthquake occurred along NEE direction, and the length of surface rupture is at least more than 70km. Around epicentral area, the width of deformation field in S-N direction is wider than that in other areas. It is determined that the maximum elevation in this area is 98cm, while the maximum subsidence is 95cm. The co-seismic horizontal displacement of the fault is about 5m.

Key words: INSAR, D-INSAR, Surface vertical deformation, Mani earthquake

摘要： 近10a来,干涉合成孔径雷达(INSAR,InterferometricSyntheticApertureRadar;简称:干涉雷达)测量技术取得了令世人瞩目的成绩,已成为极具有潜力的空间对地观测新技术。较详细地介绍了干涉合成孔径雷达、差分干涉合成孔径雷达(D-INSAR,DifferentialINSAR;简称:差分干涉雷达)技术的基本原理,并以1997年11月8日西藏玛尼地震为例,通过三通差分干涉处理,获取了玛尼地震前后的地表变形场。通过分析可知,变形梯度带与发震断层平行,均沿NEE-SWW(250°)分布,断层水平错距近5m,最大隆起斜距向位移量为98cm,最大沉降斜距向位移量为95cm。

关键词: 干涉合成孔径雷达技术, 差分干涉技术, 地表垂直形变场　玛尼地震