基于数字调幅广播外辐射源雷达的弱目标检测

摘要

外辐射源雷达面临严重的多径杂波问题,因此要实现对弱目标的检测就必须尽可能地抑制直达波、多径杂波和提高目标的信噪比和信杂比.针对这一问题,在建立新体制雷达空域、时域、频域信号模型的基础上,提出一种空域与时域联合自适应处理技术.通过空域自适应波束形成对强多径方位形成零陷,针对弱多径采用基于横向滤波器的算法从时域上消除.以数字调幅广播外辐射源雷达为例,结合仿真和实测数据对空域与时域联合自适应处理技术进行分析,能够更加有效地检测出弱目标.研究结果表明:该技术能克服空域自适应波束形成方法自由度不足或杂波噪声比低导致的杂波零陷深度不够等缺点,并且能提高目标的信噪比和信杂比.%Passive radar is confronted with serious multipath clutter problem.Therefore,it is necessary to suppress the direct wave and multipath clutter,and improve the signal-to-noise ratio(SNR) and signal-toclutter ratio (SCR) of target as much as possible.To solve this problem,a space-time domain combination adaptive technology is proposed based on the establishment of spatial,temporal and carrier-domain signal model for passive radar.In the technology,the spatial domain adaptive beamforming is used to get hulling in the direction of strong multipath clutter.And then a transversal filter is designed to eliminate weak clutter.The proposed space-time domain combination adaptive technology is used to process the simulated and measured data by taking DRM digital AM broadcast based passive bistatic radar for example.And it is proved that the proposed technology is practical,which can overcome the shortcomings of insufficient array degree of freedom and the insufficient clutter nulling depth due to low clutter noise rate in the spatial adaptive beamforming method.