基于联合谱特征的极化阵列雷达目标检测技术

Because of the large antenna gain in the main-lobe, it is very difficult to suppress the main-lobe interference received by radar receiver. Therefore how to mitigate this type of interference has been a much concerned research area in recent years. And many anti-jamming methods were proposed including polarization filtering, et al. However, when there are multiple interference sources occurring in the radar main-lobe, the signal difference between the target returns and the interference in the time-frequency-spatial-polarization domain decreases largely..The performance of the traditional methods based on Signal-Interference-Noise-Ratio(SINR) is limited. Furthermore, with the rapid increase of the number of civilian RF interference sources in the same-frequency-band and the promoted application of the cooperative jamming in the field of electronic warfare, the threat of multi-source main-lobe interference has been a realistic challenge..For the main-lobe interference problem, using the polarization array radar system and the technology approache of “feature identification” in this project, the target detection method based on the polarization-space spectrum feature are studied. This study will provide strong support for low-band radars to adapt to the complex electromagnetic environment superposed civilian RF interference and for intelligence/guidance radars to mitigate the main-lobe multi-source interference.

主瓣干扰从雷达天线主瓣进入雷达接收机，具有接收增益大的主要特点，极大地增加了抑制难度，受到雷达界的普遍关注，包括极化滤波等在内的诸多手段先后被提出，并取得了一定的进展。但是，由主瓣内同时存在多个干扰形成的主瓣多点源干扰，其与雷达目标的时-频-空-极化域差异被进一步压缩，传统基于SINR（信干噪比）的技术路线已很难进行有效抑制，随着民用射频干扰数量的迅速增长、电子对抗领域协同干扰技术的普及和应用，主瓣多点源干扰已成为一种重大威胁。本项目针对主瓣多点源干扰，立足于极化阵列雷达体制，采用“特征鉴别”的技术路线进行目标检测，研究基于极化-空间谱特征的目标检测方法，为低波段雷达适应民用射频干扰环境、情报雷达/制导雷达对抗多源协同干扰提供有力支撑。

本项目研究背景是，主瓣多点源干扰成为雷达面临的瓶颈难题，亟待创新手段予以解决。在民用方面，随着人类用频活动日益频繁，雷达（尤其是低波段雷达）受射频干扰的影响越来越严重，而在军用方面，随着战场电子对抗的升级，各种伴随式、支援式干扰大规模协同突防的情况愈加普遍，这些情况使得雷达探测正面临着日益严重的主瓣多点源干扰威胁。.主瓣多点源干扰使得传统雷达抗干扰方法难以奏效，已成为制约防空反导、战略预警、精确打击武器系统作战效能的重要威胁，是雷达界面临的重大难题。本项目创新地提出“特征鉴别”的技术路线，把干扰、目标都作为“待鉴别信号”，进一步利用有源干扰与雷达目标的特征差异判定其二元属性，提供了解决主瓣多点源干扰中目标检测难题的新途径。.本项目基于“特征鉴别实现目标检测”的技术路线，主要研究内容包括三个方面：一是立足于极化阵列雷达体制，提出了基于极化-空间联合谱特征的主瓣多点源干扰鉴别、抑制方法和目标检测技术；二是研究了阵列天线误差对检测性能的影响；三是在主瓣紧邻干扰等复杂情形下目标检测技术方面，研究了极化阵列雷达的盲源分离信号处理技术，通过联合处理有效分离多个紧邻干扰信号和目标信号，实现目标检测。.本项目所提方法，可用于极化数字阵列雷达抑制多点源干扰，特别是主瓣多点源干扰，大大提升了雷达对抗复杂干扰环境的能力。通过在某型主战雷达上开展对抗实验（主瓣内多干扰），对录取数据的处理表明，该方法可有效抑制主瓣多点源干扰。.这一成果为破解主瓣多点源干扰中雷达目标探测难题提供了重要支撑，对于应对未来与强敌作战，适应复杂干扰环境雷达探测，具有重要的意义。