双站SAR雷达目标旋转部件的微多普勒效应

Micro-Doppler Effect of Target with Rotating Part in Bistatic SAR

基于双站SAR收发系统分置的特点,建立了平飞正侧视模式下雷达目标旋转部件的回波信号模型,推导了由目标旋转引入的微多普勒频移和微多普勒调频率的参数化表达式。在该模式下,由目标转动激励的微多普勒调制不仅与其微动参数、载波波长有关,而且与收发系统的几何参数相关,从而有望在保持双站SAR较高战场生存能力等优势的情况下,通过改变系统几何配置来提高对微动目标的检测能力。最后,结合时频分析技术由数值仿真验证了理论分析的正确性。

Based on the configuration of Bistatic side-looking SAR with parallel track, the signal model of radar target with rotating part was provided, and then the mathematical expressions of micro-Doppler and its chirp-rate induced by target rotation were derived. The analysis indicates that the micro-Doppler effect is not only related to the parameters of micro-motion and carrier wavelength, but also the system geometrical configuration. So the micro-motion target indication ability can be improved by changing the geometrical configuration, while preserving relatively high viability of the system on the war-field. Finally, the theoretical analysis is verified by the simulation results.