基于LFM波形的极化雷达移频干扰鉴别

Frequency Shift Jamming Discrimination Based on LFM Waveform of Polarimetric Radar

基于数字射频存储器(Digital Ratio Frequency Memory,DRFM)的移频干扰是一种常见的针对线性调频(Linear Frequency Modulated,LFM)脉冲雷达系统的欺骗式干扰。由于LFM脉冲信号的模糊函数具有距离-多普勒耦合的特点,经移频处理后的干扰信号会对雷达接收系统产生距离欺骗的效果,常规雷达对抗移频干扰面临很多困难。该文研究了基于正负调频的LFM波形进行移频干扰鉴别的方法。通过全极化雷达的信号处理,真实目标和移频干扰会表现出差异,该文在正负调频LFM信号处理的基础上,构造了能够表现目标散射矩阵和干扰极化状态差异的特征量,该特征可以用于目标的真假鉴别。该文在给出鉴别量推导过程的同时,利用仿真数据对所提出的针对移频干扰的目标鉴别方法进行了验证,实验结果表明新的极化鉴别方法可以有效区分目标和移频干扰。

Frequency shift jamming based on digital radio frequency memory（DRFM） is a common deception jamming for linear frequency modulated（LFM） pulse radar system.Since the ambiguity function of LFM pulse signal has the characteristics of Range- Doppler coupling,the jamming signal after the process of frequency shift can generate the effect of range deception to the radar receiving system,which brings many difficulties to the conventional radar against frequency shift jamming.Frequency shift jamming discrimination based on polarimetric radar with LFM waveform which is positive and negative modulated is proposed in this paper.Through the full polarimetric radar signal processing,difference will appear between true target and jamming.In this paper,a characteristic quantity is constructed,which can show the difference between the scattering matrix of the target and the polarization state of the jamming,to distinguish between true target and jamming.The derivation of the differential amount is given in this paper,and the frequency shift jamming discrimination method is verified by using simulation data.Experimental results show that target and frequency shift jamming can be effectively distinguished by the proposed method.