针对弹载SAR景象匹配制导中匹配概率较低,需要大测绘带图像的问题,提出了通过天线距离向扫描扩大测绘带宽度的弹载扫描SAR宽测绘带成像模式.建立了弹体三维运动下的成像几何模型,给出了目标斜距表达式和回波信号表达式.通过分析扫描造成的线性距离走动空变性与多普勒中心空变性的问题,提出了改进的Range-Doppler成像算法,并分析了算法运算量.然后推导了弹体存在侧向移动时的几何校正公式.最后通过仿真验证了所提成像模式和算法的可行性.
In order to extend the swath of the SAR (Synthetic Aperture Radar) image to match the scene, the missile-borne ScanSAR wide-swath mode is studied in this paper. Firstly, the geometric model and the range equation are built, secondly the spatial variation of the linear range cell migration and the Doppler centroid are analyzed, thirdly the modified Range-Doppler algorithm and its computation load are analyzed, and lastly the geometric correction expressions are deduced. Simulation shows the effectiveness of the imaging mode and algorithms proposed.