运动测量误差对带状SAR成像影响的定量分析

Quantitative Analysis of Motion Measurement Errors on Strip Mapping SAR Imaging

定量分析运动测量误差对成像的影响是实际机载 SAR系统设计中的重要问题。本文导出了沿方位向及瞄准线同时存在恒定位置误差和恒定速度误差 ,以及同时存在恒定位置误差、恒定速度误差及恒定加速度两种情况下 ,SAR回波信号压缩波形主瓣偏移、二次相位误差、三次相位误差及四次相位误差的解析式。对 4个点目标得到的方位像仿真结果和利用文中解析式计算结果一致 ,证明了推导的正确性。

Because the accuracy of motion sensor is limited, it is extremely important to determine the effect of motion measurement errors on the quality indexes of high resolution SAR (synthetic aperture radar) imaging. An analytical equations of strip mapping SAR system quality indexes was derived, which is functions of six errors such as constant position, velocity and acceleration errors along both azimuth and range direction, rather than five errors. The main lobe deviation, two, three and four order phase errors were calculated. The effect of these errors of GPS/SINS integrated system on SAR cross imaging of four point targets was simulated. Simulation result show that the derived equations are correct.