双基机载雷达的杂波谱补偿方法

Compensation of the clutter spectrum for a bistatic airborne radar

双基机载雷达结构中杂波多普勒频率是随距离和双基结构发生变化的,使杂波谱在距离上呈现严重的非平稳性,导致杂波协方差矩阵估计困难.针对此问题提出一种基于最小二乘的空域导向矢量拟合的杂波谱补偿方法,先将训练单元上的空域导向矢量向待检单元的空域导向矢量投影得到一个变换矩阵,用这个矩阵对训练单元上的数据进行预处理,消除杂波谱的非平稳性,得到足够的统计数据,从而构造新的杂波协方差矩阵,最后利用空时自适应算法对补偿后的数据进行杂波抑制.仿真结果表明该方法能够有效地抑制地杂波的非平稳性,提高雷达杂波抑制的性能.

The clutter spectrum depends highly on the range and frame of bistatic airborne radars, which results in heterogeneous ground clutter and inaccurate estimation of the clutter covariance matrix in spacetime adaptive processing （STAP）. A new method for the compensation of the clutter spectrum is proposed. The method first gives a transform matrix by fitting the spatial steering vector of the range gate under test to that of the secondary range gate. The transform matrix is then applied to spatial data at a given Doppler gate to compensate the clutter spectrum, thus achieving an identical clutter spectrum. The conventional STAP could exploit the compensated data for the clutter suppression. Simulation results show a good improvement in processor performance.