单通道SAR实现ATI动目标检测的新方法

研究了采用单通道合成孔径雷达(SAR,Synthetic Aperture Radar)多视沿航迹向干涉(ATI,Along Track Interferometry)实现地面慢速运动目标指示的检测方法.分析了该方法所需的步骤,即利用重叠或不重叠的窗构造子视,对子视分别成像,相位误差校正并求干涉.关于其中起关键作用的相位误差校正步骤,提出了利用信号子空间投影进行相位配准的补偿方法.借助该鲁棒的自适应方法可以从某种程度上解决子图像间的去相关问题,降低相位随机性的影响,从2幅子视图像的干涉相位图上敏锐地检测到运动目标.通过仿真实验,验证了该方法可以有效地从强杂波中检测动目标,为单通道SAR实现地面运动目标指示(GMTI,Ground Moving Target Indication)、扩展已有SAR系统功能提供可靠的途径. 

New method of moving target detection using single-channel SAR ATI

A detector for slow GMTI(ground moving target indication) with a single channel SAR(synthetic aperture radar) multi-look ATI(along track interferometry) was investigated.The steps include constructing multi-look using overlapped or unoverlapped windows,respective imaging,phase compensation and performing interferemetric processing.Concerning the crucial step of phase error rectification,a compensation method of phase calibration using SSP(signal subspace processing) was proposed.By this robust and adaptive approach,decorrelation between sub-images can be resolved and phase randomicity of multi-look ATI can be alleviated to some extent,moving targets can be isolated much easily from interferometric phase of multi-look sub-images.Simulation results show effectiveness of the method in moving targets detection in strong clutter,thus it provides reliable reference for single channel SAR GMTI and supports operational extension of existing SAR system.