多基地极化雷达主瓣干扰抑制算法

现代战场电子对抗日益复杂，电磁干扰形式多样，当干扰从接收机主瓣进入会形成主瓣干扰。主瓣干扰严重影响雷达正常工作，传统空域、极化域、时频域等抗干扰算法都很难有效对其抑制。为有效抑制主瓣干扰，文章利用目标极化散射特性在不同角度存在差异的特点，提出基于多基雷达的空-极化协同滤波主瓣干扰抑制方法。方法首先采用主瓣保形技术在空域抑制副瓣干扰并压低空间噪声，然后将多基地雷达接收的数据进行时域对齐，计算包含主瓣干扰和回波信号的数据协方差矩阵，通过分解协方差矩阵在空-极化信号空间识别干扰，估计回波信号导向矢量，最后将目标回波与主瓣干扰通过多基地极化滤波，滤除主瓣干扰保留目标回波信号。通过仿真算法抑制噪声干扰与转发干扰，验证了所提算法能够有效对抗主瓣干扰，有效提高输出信干噪比。 

Multi-base polarization radar main-lobe interference suppression algorithm

Modern battlefield electromagnetic confrontation is increasingly complex, and there are many kinds of electromagnetic interference. The interference will form the main-lobe interference when it comes into the receiver main-lobe. Traditional anti-interference method in space polarization and time-frequency domain is hard to suppress the main-lobe interference. And the performance of radar is affected severely. Aimed at the problem of main-lobe interference suppression, space-polarization filtering method based on multi-base radar is developed. It takes advantage of the difference of target polarization scattering characteristics in different scattering angles. Firstly proposed method suppresses side-lobe interference and spatial noise in space domain using main-lobe shape preserving technique. Then calibrate time delay and calculate the covariance matrix of data including main-lobe jamming and echo signal. Then recognize main-lobe jamming in space-polarization signal space through the decomposition of covariance matrix, and estimate echo signal steering vector. Finally acquire target echo signal by multi-base space-polarization filtering. The main-lobe interference is filtered in echo signal subspace and echo is remained. Through simulation of suppressing noise and repeater interference, it proves that proposed method can suppress main-lobe interference effectively, and enhance output signal to interference and noise radio.