Abstract: In this paper,we modeled earthquake co-seismic deformation field using a linear elastic model in half-space with a strikeslip earthquake fault. Afterward, we got coseismic deformation field in LOS direction, descending and ascending pass InSAR results with two kinds of radar imaging geometry respectively, and made comparative analysis of results with different SAR bands (X, C and L) and different SAR incidence angles (30°and 50°). The results show that, in the same band, the InSAR results contains different effective information with different incidence angles. The deformation field in LOS direction increases with the increase of incidence angle, reflecting the characteristics of the seismic fault. The detected vertical component and horizontal component of the surface deformation by InSAR differ with different incidence angle. Larger or smaller incidence angle can be used to well detect horizontal deformation or vertical deformation respectively. In the same incidence angle, fringes of the InSAR results are obviously different with different wavelengths. With shotee wavelength, the rate of the fringe is higher, resulting in incoherence phenomena. In contrast, the fringe with longer wavelength is relatively clear. In a sense, using longer wavelength may result in more usable interferometric pairs, and the InSAR result are less affected by noise, although it may contain less precise crustalmotion measurements. The surface deformation is not only embodied as long-term, slow and gradual change, but also embodied as shortterm, rapid and large change. Radar with different wave length can detect different effective information about surface deformation. In order to better detect surface deformation with different rate and various scale of changes by using InSAR, it is necessary to use the longest radar wavelengths possible within some limits, and multiple observations.

Key words: Co-seismic deformation, Linear elastic model, SAR interferometry, Radar band, Random noise