In order to meet the increasing demand for SAR raw signal and SAR images simulation

a new method for the simulation of the SAR raw signal and images of typical terrains is proposed in this paper.The properties of Fractal Brown Sur-face and its horizontal are analyzed first.Then the Digital Elevation Model（DEM） of the mountain terrains is generated by the usage of random MPD（Middle Point Displacement） method.The new approaches for the generation of coastal terrain（Re-turn-to-Zero method） and river-ravine terrain（Return-to-Zero-Inversion method） are also proposed.The back scattering coeffi-cient of each resolution cell is calculated by employing the corresponding electromagnetic scattering model.The algorithm of SAR raw signal simulation based on the 2DFFT（two-dimensional Fourier Transform） is presented.The simulation results show that the proposed method is valid.