本文研究多孔径合成孔径雷达(SAR)通道间的失配问题,提出了一种在两个SAR原始数据域进行两步滤波的通道均衡方法。针对天线波束方向图差异进行距离多普勒域上的幅相滤波,在距离频域方位时域进行的幅相滤波针对的是频率响应差异。在第一步滤波中,为消除通道间的确定性差异,对高相干性区域构造一个自适应滤波器,对噪声区域则采用非自适应滤波。经过第二步滤波后,噪声被滤除,剩余就是运动目标信号。机载实测数据处理验证了原始数据域通道均衡方法的可行性。
The channel mismatch problem was investigated in multi-aperture Synthetic Aperture Radar(SAR).A channel balancing technique based on the two-stage filters in the different raw data domains was presented.The amplitude and phase filter in the range Doppler domain corresponds to the antenna beam pattern difference,and the filter in the range frequency azimuth time domain corresponds to the frequency response difference.In the first stage filtering process,we constructed an adaptive filter in the region with higher coherence,and a non-adaptive one in the noise dominated region to remove the deterministic difference between channels.In the second stage filtering process,the noise was removed and only the target signatures were left.The feasibility of the channel balancing algorithm carried out in the raw data domain is demonstrated with the measured airborne data.