星载合成孔径雷达(SAR)空间几何关系误差分析

Analysis of Spaceborne Synthetic Aperture Radar Geometric Error

本文以星载ＳＡＲ卫星平台和地面目标的空间几何关系为基础，给出了星载ＳＡＲ多普勒参数数学模型，分析了卫星运动、平台姿态、地球旋转、目标高度等几何参数误差对测绘带上的多普勒参数、零多普勒偏移、目标位置等星载ＳＡＲ处理参数的影响，说明了采用“偏航调整”方法（ｙａｗｓｔｅｅｒｉｎｇ），可以使天线波束中心位置指向零多普勒方向而降低多普勒中心频率。最后以航天工业总公司论证的Ｃ－ＳＡＲ系统参数进行了仿真实验，计算结果与理论分析相吻合。

On the basis of the spaceborne SAR geometry between the satellite platform and the target, Doppler parameter models are given, and the effects of satellite orbit, attitude, the earth rotation and target height on the Doppler parameters, zero Doppler shift and target position are analyzed. Furthermore, the yaw steering mode is shown to approximately steer SAR antenna towards the zero Doppler line to reduce the Doppler center frequency. At last, the simulation experiments are presented in terms of the C SAR system parameters demonstrated by Chinese Aerospace Corporation. The calculation results accord with the theoretical analysis. [WT5”HZ〗