极化-空域联合抗机载雷达欺骗式主瓣干扰

摘要

机载雷达欺骗式主瓣干扰不仅会引起大量虚警，还会污染空时自适应处理(STAP)器的训练样本，引起自适应方向图畸变，导致期望信号相消和杂波抑制性能下降。针对此问题，利用目标信号与干扰信号极化特性的差异，该文提出一种极化-空域联合自适应波束形成的方法来抑制欺骗式主瓣干扰。该方法首先在多普勒清晰区挑选干扰样本，并采用特征融合技术估计干扰协方差矩阵，然后采用重叠滑窗的子阵合成方式进行极化-空域联合自适应波束形成，在抑制主瓣干扰的同时为后续杂波抑制保留了空域自由度，最后通过 STAP 抑制剩余的杂波。该算法可以有效滤除密集欺骗式干扰，减少由其引起的虚警，改善机载 STAP 雷达的杂波抑制性能。仿真结果验证了该方法的有效性。%The deceptive mainlobe jamming of airborne radar not only causes a large amount of false alarms but also contaminates samples of the Space-Time Adaptive Processor (STAP). Hence, the performance on clutter suppression is degraded and signal self-cancellation occurs due to the distorted adaptive pattern. A polarization-space adaptive beamforming algorithm utilizing the polarization difference between the target signal and jamming is proposed for suppressing the deceptive mainlobe jamming. Firstly, the eigen-fusion based jamming covariance matrix is estimated by the samples obtained from clutter-free Doppler zone. Then, the polarization-space adaptive beamforming algorithm is carried out via synthesizing subarrays with overlapped window. This algorithm has the ability to suppress mainlobe jamming and retain the spatial degree of freedom for clutter suppression. Finally, the STAP is utilized to suppress the residual clutter. The proposed method can efficiently suppress the dense deceptive jamming, and hence, reduce the number of false alarms. The performance of STAP for clutter suppression can also be improved. Simulation results verify the effectiveness of the proposed method.