Study On Echoed Signal Simulation Of Airborne SAR

Airborne Synthetic Aperture Radar (SAR) simulation plays an important role in the process of SAR development. Of which SAR echoed signal's simulation is the fundamental part. The main research work of this dissertation are based on the airborne SAR echoed signal's simulation, does some work to the effect in the simulation system of SAR in the laboratory in advance.There are two parts in the paper. The first part of this thesis is about the model of the SAR echoed signals, which is based on collection of scattered centers. Like the principle of SAR, two waveforms of transmitted signal, linear frequency modulated waveform and stepped frequency waveform, are adopted. The expressions of echoed signal models and the method of imaging are got in the wideband condition.The second part concerns the simulation and imaging of the model. The character of SAR picture is analyzed in detail, the R-D or Chirp-Scaling algorithm and processing for build image's parameters are introduced. The simulations of some objects have been carried out. Then the computer program has been developed and some satisfactory SAR images were obtained.The contents of the papers are as follows, the background and the meaning of the researches on SAR echoed signals are reviewed at first. In the first chapter of the thesis, the airborne SAR and some different simulation methods are also introduced. After the first one, the principle of high resolution imaging technique used in SAR is described in detail. The third chapter is about the model of SAR echoed signal with linear frequency modulated signal based on collected scattered centers. In the fourth chapter, the model of the SAR echoed signal with stepped frequency signal is presented. Based on the models above, some simulations of different objects are completed. Finally is the summation of the jobs in this paper.