机载干涉SAR运动补偿中地物目标定位误差的影响分析

摘要

The measurement inaccuracies of Inertial Measurement Unit/Global Positioning System (IMU/GPS) as well as the positioning error of the target may contribute to the residual uncompensated motion errors in the MOtion COmpensation (MOCO) approach. Aiming at the effects of target positioning error on MOCO for airborne interferometric SAR, the paper deduces a mathematical model of the residual motion error caused by the target positioning error under the condition of squint. Also, the effects of the system sampling delay, Doppler center frequency, and reference DEM errors on the residual motion error that result in target positioning error based on the model are analyzed. Then, the paper discusses the effects of the reference DEM error on the interferometric SAR image quality, the interferometric phase, and the coherent coefficient. The research provides theoretical basis for the MOCO precision in signal processing of the airborne high precision and airborne repeat-pass interferometric SARs.%在基于IMU/GPS测量数据的运动补偿方法中，IMU测量误差和地物目标定位误差导致不准确的相位补偿量，从而引入残余运动误差。该文针对机载干涉SAR运动补偿中地物目标定位误差的影响，建立了在斜视条件下由地物目标定位误差引入的残余运动误差的数学模型，分析了导致地物目标定位误差的系统采样延时误差、多普勒中心频率误差和参考DEM误差对残余运动误差的影响，重点讨论了参考DEM误差对干涉SAR图像质量、干涉相位和相干系数的影响。该文的讨论结果为机载高精度 SAR 和重轨干涉 SAR 数据处理中运动补偿精度提供了理论基础。