斜视SAR分数阶距离多普勒成像算法

摘要

针对传统距离多普勒(RD)算法在斜视合成孔径雷达(SAR)成像时运算置不足和边缘存在干扰的问题,将传统的RD算法中的匹配滤波用分数阶Fourier变换替代,提出基于分数阶Fourier变换SAR斜视距离多普勒成像(FrRD)算法.理论分析斜视SAR回波信号分数阶Fourier变换域模型,徙动校正在距离分数阶Fourier域方位频域完成,给出FrRD算法仿真流程.仿真结果表明,与传统RD算法相比,FrRD算法成像副瓣更低,成像边界更加清晰,成像时间缩短近一半.%Focusing on the issue of squint Synthetic Aperture Radar(SAR) imaging which has th lack of computation and the interference in edge with the traditional RD algorithm, the Fractional Fourier Transform(FRFT) instead of matched filtering in traditional RD algorithm, and Range Doppler imaging algorithm based on fractional Fourier transform(FrRD algorithm) for squint mode SAR is proposed. The theoretical model of squint mode SAR echo in fractional Fourier domain is analyzed. The model derives that migration correction is completed in the range fractional Fourier domain and azimuth frequency domain. Simulation results show that compared with the traditional RD algorithm, by using FrRD imaging algorithm for squint mode SAR, the side-lobes is lower, the border is clearer, and the imaging time is nearly a half.