针对慢速运动目标在时域和频域上都落入主杂波区不易被检测的特点, 提出一种三通道条件下机载合成孔径雷达地面动目标检测(SAR-GMTI)方法。采用相位中心偏置天线技术(DPCA)对消杂波, 利用分数阶傅里叶变换(FrFT)估计剩余的动目标参数, 再构造方位压缩参考函数对场景成像。该方法充分利用三通道的信息余度, 发挥DPCA稳健的杂波对消能力和FrFT的良好能量聚焦性能, 能够实现对包括径向加速度等在内的目标参数精确估计。实验仿真结果验证了本方法的有效性。

It is difficult to detect a target with a low speed since it may drop into main lobe clutter in both time domain and frequency domain. A multi-channel SAR-GMTI algorithm was proposed to solve this problem which can suppress the clutter with Displaced Phase Center Antenna (DPCA) estimate the parameters of moving target with Fractional Fourier Transform (FrFT) and acquire the scene image by constructing the azimuth compression function. The proposed approach takes full advantages of the abundant information of three channels makes use of the ideal clutter cancellation capability of DPCA technique and the fine energy focusing ability of the FrFT which can estimate the parameter of moving target accurately including radial acceleration. The results of the simulation indicate the effectiveness of the methods.