机载聚束式SAR天线波束指向控制分析

建立波束控制条件下的机载聚束式SAR的天线指向及成像数学模型,证实天线波束指向被控造成回波信号的幅度调制,引起成对回波,从而影响成像质量。此外,分析波束指向控制比率与测绘带方位宽度、图像动态范围的制约关系,提出设计机载聚束式SAR天线波束指向控制比率的基本原则。最后,通过计算机仿真,验证理论分析的正确性。

Analysis of Air Spotlight SAR Antenna Beam Point Steering

In the condition of beam point steering,the air spotlight SAR antenna model and imaging model are found. The math analysis confirms that beam point steering resulted in echo amplitude being modulated and caused infinite pairs of echoes. So beam point steering would deteriorate image quality. Besides, based on the analyses of tradeoff relation of beam point steering ratio, imaging area azimuth width and image dynamic extent, the fundamental principle of designing beam point steering ratio is presented. Finally, point target simulation is given and simulation result prores the validity of theoretical analysis.