对空时自适应处理雷达的投散射式伪杂波干扰方法信号特性分析

摘要

针对宽带噪声干扰在空时自适应处理(Space-Time Adaptive Processing,STAP)雷达功率凝聚工作模式下无法有效掩护被保护目标方位信息的问题,提出了一种投散射式伪杂波干扰方法,分析了干扰信号在雷达接收端的空时特性.该方法通过向地面特定区域投射经过调制转发的雷达信号产生类杂波干扰信号.该信号多普勒频率与方位耦合、具有空间连续性与时间连续性,空时功率频谱轨迹可控.推导了干扰信号空时矢量模型,从雷达接收机的角度分析了干扰给目标检测带来的影响;在研究干扰信号多普勒轨迹分布特性与等值多普勒曲线分布特性的基础上,提出了干扰空时协方差矩阵特征值数目估计方法.仿真结果表明,该方法产生的干扰空时功率谱呈背脊线分布,使STAP处理器出现多个凹口,有效保护了目标信息.%The wide-band noise jamming method fails to conceal the azimuth information of the target in the power condensation pattern.Therefore,a scattered-wave jamming method is proposed.The fake clutter signal is generated by scat-tering radar signal with Doppler shifting to the certain areas from jammers.The jamming signal acquires space-time coupling and is continuous both in space domain and time domain.The trajectory of jamming space-time power spectrum is controlla-ble.The effect of radar target detection is analyzed by deriving the mathematic model of jamming signal.Furthermore,ac-cording to the Doppler trace feature and the Doppler isoplethic curves characteristic of the jamming signal,the estimation al-gorithm of the clutter and jamming covariance matrix eigenvalue number is proposed.The simulation results indicate that the shape of jamming space-time power spectrum is similar to bias,which leads to the improvement factor of STAP radar appea-ring more than one nocth.