SAR Ground Moving Target Detection Based On Space-Time-Frequency Processing

Multi-channel SAR-GMTI has been one of the hot topic researches. It has been widely used for military and civilian field, due to the perfect performance in moving target detection and high resolution imaging. This thesis thoroughly studies the combined space-time-frequency processing for the moving target detection and the parameter estimation. Our analytic works in concrete are mainly as follows:(1) Based on the stationary target echo model, the echo model of the moving target is constructed. The influence of the target motion on the imaging result is analyzed. As for the characteristic of the moving target echo, the principles and implement method of Fractional Fourier transform are introduced in detail for parameter estimation.(2) DPCA(Displaced Phase Center Antenna) and ATI(Along Track Interferometry) are used for the moving target detection and the corresponding principle is analyzed. Then, these two methodologies are combined with FrFT(Fractional Fourier Transform) to estimate the parameters. Moreover, two improved methods, including two channel DPCA-FrFT and two channel DPCA-ATI-FrFT, are proposed. Theoretical derivation and experimental results have verified that the proposed methods can achieve significant improvement in moving target detection and parameter estimation by using less channels.(3) Based on the analysis of the space-time adaptive processing, multi-channel SAR STAP is discussed. Then, the implement method combined with FrFT is analyzed for parameter estimation. As for the drawback of heavy computation, a new method is proposed by using two steps for the moving target detection. The first step is a coarse detection by the low resolution data, and the second step is fine detection by the original data. The proposed method can effectively reduce the amount of the computation.