Research On Target Imaging Simulation Of Synthetic Aperture Radar

Imaging simulation technology plays an important role in the research and development of airborne SAR, in which the basis of SAR echo signal simulation and imaging simulation is to build SAR target distributing model. This thesis mainly studies about the scatting characteristics and imaging simulation of airborne SAR target and its background. In the process of building target distributing model, component disassembly method is used to built 3D geometrical model of target at first, then the target electromagnetic scattering model is built aiming to the given target. On the assumption that the target surface roughness is more less than wavelength, then the scattering characteristic of this kind of less roughness surface is studied by physical optics method and perturbation method, therefore the target electromagnetic scattering model is built, and also statistics characteristic of target background scattering field is studied. The target electromagnetic scattering model is applied to the SAR simulating system and thus a radar reflection echo signal model is built, which is analyzed by surface integral model, that is to say, the surface integral is performed to the whole radar wave irradiation area, calculating method of discrete on echo signal model is also discussed. This thesis also introduces two kinds of mature SAR imaging method, Range-Doppler algorithm and Chirp-Scaling algorithm, which have been simulated and realized under Matlab environment. Finally, the imaging simulation test of airborne sideway SAR to the fixed target on the ground is carried out by using the Range-Doppler algorithm, accordingly the ideal simulating images have been obtained.