反舰导弹聚束式SAR导引头成像算法研究

针对反舰导弹聚束式SAR导引头大前斜视角及成像处理时间短的工作特点,将基于最小熵准则的RD算法及改进FS算法用于导引头锁定目标阶段的成像。基于最小熵准则的自聚焦RD算法在一般RD算法的基础上引入最小熵准则来补偿由于大斜视角引起的相位误差,改善图像聚焦效果。改进的FS算法引入了SRC的非线性变标对数据进行二次距离压缩,有效地减少了距离压缩误差。仿真结果表明:两种算法在斜视角达75°时,改进的FS算法能达到较好的成像效果。

Study on Imaging Algorithms of Spotlight Synthetic Aperture Radar Seeker for Antiship Missile

Based on the work characteristic of high squint angle and short imaging disposing time for the antiship missile Synthetic Aperture Radar Seeker(SARS),uses RD algorithm based on minimum entropy criteria and modified frequency scaling algorithm to process spotlight SAR data on the SARS's locking target moment.RD algorithm based on minimum entropy criteria carries out the correction phase errors caused by high squint angle via searching error coefficients for improving the imaging focus effect.A nonlinear scaling operation is adopted to cope with the range-dependent SRC in modified frequency scaling algorithm,which minishes SRC error effectively.The simulation result shows,between these algorithms,the imaging from modified frequency scaling algorithm is better when the squint angle is up to 75 degree.