初始姿态精度对SAR成像分辨率的影响

分析了合成孔径雷达SAR运动补偿用惯导初始对准误差对SAR天线相位中心运动参数测量精度以及成像分辨率的影响.通过建立惯性器件误差→惯导初始自对准精度→SAR成像分辨率三者之间的量化映射关系,可以直观地发现,SAR合成孔径起始时刻姿态误差对成像分辨率的影响较之初始位置、速度误差更为严重,并分析指出不同方向的初始姿态误差对SAR成像分辨率的影响并不相同,由此进一步分析了SAR运动补偿系统惯导器件对成像分辨率的影响.经过单个点目标SAR成像(RD算法)仿真验证了该方法的正确性.

Influence of initial alignment precision in motion compensation subsystem on SAR imaging resolution

Inertial navigation system(INS) is a critical component of SAR(synthetic aperture radar) motion compensation systems.The influence of the INS initial alignment error on motion compensation precision and SAR resolution is analysed.The mapping relationship between INS initial alignment error and SAR resolution is established.Analysed from the relationship,the attitude initial alignment error is much more important than the position and velocity initial alignment error at the beginning of SAR coherent time,and the attitude initial alignment errors in different direction cause different degradation of SAR resolution.The influence of inertial devices errors on SAR resolution is eliminated by taking the advantage of the mapping relation between inertial device error and initial alignment precision.Emulations of SAR imaging of the single point target show that the above conclusion and relationship are correct.