在机载合成孔径雷达/地面动目标指示(SAR/GMTI)应用中,各误差因素常使得沿航迹干涉(ATI)方法失效,限制其实际应用。推导并仿真了同步定时误差和姿态误差引入干涉相位误差,导致ATI动目标检测性能下降的情况,提出了一种基于信号子空间处理的解决方法,并对以上误差情况分别进行了分析和校正。仿真结果表明,该方法可使ATI对误差因素的敏感度下降,从而提高动目标检测性能,扩大ATI的适用范围,具有一定的工程参考价值。
A main problem of airborne synthetic aperture radar/ground moving target indicator(SAR/GMTI) based on the along track interferometry(ATI) technique is that varieties of error invalidate ATI and limit its application. The interferometric phase error which causes the performance decline in ATI ground moving target detection due to synchronization error and platform attitude error is analyzed and is investigated with detailed deduction. Signal subspace processing based on 2-D adaptive filtering is introduced to calibrate these errors and the moving target detection is achieved. The simulation results indicate that the scheme can reduce the sensitivity of ATI to errors and improves the performance of moving target detection.