双天线旋转目标微多普勒特征分析

Micro-Doppler Signatures Analysis of Spinning Target with Double-antenna

在旋转目标的飞行过程中,目标的旋转会在回波信号中产生微多普勒调制。合作式的旋转目标常通过机载应答机进行信息传输,理论与仿真分析发现在双天线信号传输模式中,弹体的遮挡效应会对接收信号中的微多普勒调制产生影响。通过建立应答式目标的微多普勒模型,分析应答机天线相对位置与微多普勒相位特征的关系,推导了双天线条件下地面接收信号的微多普勒调制特征,给出了对应时频特征下的接收信号模型,并分析了天线切换带来的实测信号间断性问题,结合信号时频特征提出下一步可行的信号处理方法。

During the flying course of a spinning target, the receiving signal will be modulated by micro-Doppler. Through theoretical and simulative analysis of the cooperative target which usually transmits by transponder,it is found that the eclipsing effect in the signal transmission mode with double-antenna will af-fect the micro-Doppler modulation of receiving signal. The relationship between the relative position of tran-sponder antenna and the phase characteristics of micro-Doppler is analyzed by modeling the micro-Doppler model of cooperative target. The modulation signatures of micro-Doppler of the receiving signal are deduced in double-antenna condition and the receiving signal model with corresponding time-frequency feature is given. Then the intermittency of the measured signal caused by the switch of antenna is discussed. Finally, the next viable signal processing methods are presented according to the time-frequency feature.