Typical Terrain Modeling And SAR Image Simulation Based On Fractal

This paper makes deep research on terrain simulation using fractal techniques. Based on the theory of fractal Brown motion, mid-point displacement algorithm is improved,and the digital model of terrain generated by using the improved algorithm shows that, the predetermined shape is preferably generated and characteristics of the natural terrain is preferably reappeared. Based on the research of SAR imaging principle, simulations of SAR image of the digital terrain are carried out.At first, the background and principle of fractal geometry are introduced, the technique characteristics, developments and application of FBM are also studied. MPD algorithm is presented based on FBM, which is the theoretical foundation of terrain modeling. The fractal properties of the natural terrain and portfolio FBM model are analysed, for studying the method to reflect natural features of real scene, and improves MPD algorithm to simulate the portfolio FBM model. Through the analysis of the influence of different parameters, the method to gain terrain feature analysis data is explained, and the research about improving MPD algorithm to control digital terrain structure is presented. Integrating with the improvement of MPD algorithm above, the model of terrain is simulated, which shows that the predetermined shape is preferably generated and characteristics of the natural terrain is preferably reappeared. The results of experiments improves that the method of terrain modeling is feasible and effective. Then based on the generated terrain model as research objects, the research about the radar scatting characters of natural terrain and the computing model of backscattering coefficients is explained. Integrated with the geometrical distortions of SAR images, the simulation results of backscattering coefficients of background target is gained by experiments, which reflects the true backscattering characteristics of terrain background. After studying the model of the SAR echoed signal and the method of imaging, the problem of speckle is discussed. Finally, the simulations of SAR images of terrain model are finished, and some satisfactory SAR images are obtained.