曲线轨迹SAR大斜视子孔径成像算法

摘要

针对小型合成孔径雷达(synthetic aperture radar, SAR)平台曲线轨迹运动、大斜视实时成像的要求,提出一种子孔径成像算法,首先进行预处理,补偿加速度对调频率的影响,再采用级数反演法(method of series reversion, MSR)得到回波信号的高阶近似二维谱.在此基础上,基于方位频域相位滤波处理校正方位调频率空变,最终利用谱分析(spectrum analysis,SPECAN)技术实现方位统一聚焦.点目标仿真数据验证了本文算法的有效性.%Due to the problems of curved trajectory and real-time imaging requirement in the small synthetic aperture radar (SAR) platform, a sub-aperture algorithm is proposed for high squint mode SAR data focusing.First, the preprocessing is taken to remove the effect of acceleration on azimuth frequency modulation rate.After the preprocessing, the expressions of echo signals in 2-D frequency domain are derived by the method of series reversion (MSR).Then, the space-variant of azimuth frequency modulation rate is corrected by azimuth frequency domain phase filtering (FDPF).Finally, the azimuth uniform focusing is done in the azimuth frequency domain by the spectrum analysis (SPECAN) technique.Simulation results validate the proposed algorithm.