大带宽高分辨力多通道SAR频谱重构

摘要

针对大带宽高分辨力SAR的幅相误差特性,提出了基于通道幅相误差补偿的偏移相位中心多通道SAR频谱重构算法.该算法利用雷达内定标数据估计通道内和通道间的系统幅相误差并补偿回波数据,然后通过频谱重构滤波器抑制模糊多普勒频率信号,获得无模糊的多普勒信号.仿真和实测数据的成像结果表明,该算法能够有效抑制高分辨力多通道SAR的模糊多普勒分量,获得满意的成像效果.%Considering the amplitude-phase error property of the wide bandwidth SAR with high azimuth resolution, an innovative unambiguous spectrum reconstruction algorithm adopted in multi-channel displaced phase centre ( DPC) SAR system is proposed. The algorithm is constructed based on the amplitude-phase error compensation. The amplitude and phase errors of inter and inner channels are estimated by using the radar internal calibration data, and the echo data are compensated. Then the aliasing Doppler spectrum of the compensated data is depressed by the reconstruction filter and the unambiguous Doppler spectrum is recovered. The imaging results of simulation and SAR data show that the algorithm can effectively suppress the Doppler ambiguity and satisfy the imaging requirement.