弹载双基前视 SAR 建模及运动/同步误差分析

摘要

Missile-borne bistatic forward-looking synthetic aperture radar (MBFL-SAR)is a new and spe-cial imaging mode,which is the application of bistatic forward-looking synthetic aperture radar to the missile platform.It could perform two-dimensional (2D)imaging and passive homing during the whole terminal diving period of the missile.This paper establishes the echo slant range model under high dynamic conditions according to the moving feature of MBFL-SAR.And then motion parameters such as the Doppler frequency and the Doppler chirp rate are analyzed compared with the traditional bistatic platform with low velocities.Further-more,error models of the slant range history,the Doppler frequency,the Doppler chirp rate and synchroniza-tion in the presence of motion errors are built.And restrictions of motion parameters and precision requirements of synchronization errors are developed based on the influence of errors on imaging performance of MBFL-SAR. Simulation results show the validity of the proposed error models.%弹载双基前视合成孔径雷达(missile-borne bistatic forward-looking synthetic aperture radar,MBFL-SAR)是一种将双基前视 SAR 成像体制应用于弹载平台的新型 SAR 成像模式,可实现弹载雷达末端俯冲阶段全程二维成像、自主寻的精确制导。结合 MBFL-SAR 的运动特点,建立了高动态条件下的回波距离模型,并就多普勒频率和多普勒调频率等参数与常规低速双基平台模式进行了对比分析。在此基础上建立了高动态条件下存在运动误差情形的斜距历程、多普勒频率及多普勒调频率误差模型和同步误差模型,并基于误差对 MBFL-SAR 成像的影响给出了运动参量的约束条件和同步误差的精度要求。仿真结果验证了误差模型的正确性。