一种机载非正侧视阵雷达近程杂波对消方法

Short-range clutter elimination method for non-side looking airborne radar

机载预警雷达发射中高脉冲重复频率信号时,会导致接收杂波存在距离模糊现象。对于机载非正侧视阵雷达(non-side looking airborne radar,non-SLAR),其近程回波具有强烈的距离依赖性,导致通过统计方法估计的杂波协方差矩阵不准确,使得空时自适应处理(space-time adaptive processing,STAP)的杂波抑制性能急剧下降。接收天线为均匀线阵条件下,由于阵列没有俯仰维自由度,无法直接对近程杂波进行抑制。针对这种情况,提出了一种近程杂波对消方法,该方法首先估计出近程模糊距离门对应的俯仰角,然后利用空时二维杂波谱的先验信息对近程的杂波进行估计,最后对原始的接收数据进行近程杂波对消。该方法能够对近程杂波进行有效抑制,获得的杂波抑制性能高于直接处理法。仿真实验结果验证了该方法的有效性。

The short-range clutter presents severe range dependence for non-side looking airborne radar （non-SLAR）. Due to the absence of elevation degree of freedom, the uniform linear array cannot directly sup press the short-range clutter with range ambiguity. As a result, the clutter plus noise covariance matrix cannot be estimated accurately which greatly declines the clutter suppression performance by space-time adaptive pro- cessing （STAP）. To overcome this problem, a short-range clutter elimination method is proposed. Firstly, the elevation angle of the short range i evaluated. Then the short-range clutter is reconstructed by the information of the clutter spectrum, and the short-range clutter to all received channels by adaptive processing is eliminated. Finally, reduced demensional space-time adaptive processing （RD-STAP） technique is adopted to suppress the residual clutter. The proposed method can eliminate the short-range clutter effectively. Simulation results dem-nstrate the validity of the method.