星机双基地合成孔径雷达方位向成像性能分析

Analysis of coverage and integration time in spaceborne/airborne bistatic synthetic aperture radar configurations

星机双基地合成孔径雷达系统中,由于收发平台运动速度差异较大,因此需要对收发波足(波足是指波束在地面的投影)的运动速度进行合理的设置,减小收发波足速度差,尽可能地提高收发波足覆盖范围和时间,进而实现高分辨率、大方位场景成像。根据收发波足覆盖时间的相互关系,分析收发波足共同覆盖范围内的方位向成像性能。分析收发波足方位向位置偏移对方位向成像性能的影响,从而对星机双基地合成孔径雷达系统的波束同步精度提出要求。仿真结果表明,所提出的方法能够很好地分析收发波足同步误差对成像性能的影响,能够为星机双基地合成孔径雷达系统设计提供重要参考。

Due to the big difference between the velocities of the transmitter and the receiver, the working mode should be reasonably designed to realize high resolution and extended scene in SA-BiSAR （ spaceborne/airborne bistatic synthetic aperture radar system）. Based on the ratio of the beam width to the velocity, a scheme for the computation of integration time and azimuth coverage of SA-BiSAR was described. A classification of bistatic SAR（synthetic aperture radar） configurations was introduced in terms of the antenna footprints, size and the velocities. At the same time, accurate effect of the initial footprints offset on the image performance in azimuth direction was obtained. Simulation results validate that the proposed method can be well used for footprint synchronization error analysis and SA-BiSAR system design.