基于交替投影的DOA估计方法及其在米波雷达中的应用

由于低仰角目标回波中存在多径信号,使得米波雷达难以对低仰角目标进行高度测量,为此该文提出一种适用于多径信号情况下的波达方向估计的迭代方法.该方法将回波信号的相关矩阵,在各个信号子空间中交替投影,该方法可以同时对直达波和反射波进行精确的波达方向估计,并可以有效地对米波雷达中的低仰角低空目标进行高度测量.计算机仿真和某米波雷达实测数据的处理结果证实了该方法的有效性.Monte-Carlo试验结果表明在低仰角低空测高时,该方法具有比时空级联最大似然方法更好的性能.

A New DOA Estimator Based on Alternating Projection and Its Application in VHF Radar

In the presence of multi-path propagation, it is quite difficult for VHF radar to measure the altitude of a low elevation target. In this paper, a new alternating projection algorithm is proposed to estimate the DOA of the target. By projecting the correlation matrix of the target echo into different signal subspaces, this method can be used to estimate accurately the directions of both the direct wave and the reflected wave, and hence the altitude of the target is known precisely. Results of both computer simulation and the real data from some VHF radar demonstrate the validity of the new algorithm. The Monte-Carlo experiment proves that the performance of the new algorithm is better than that of the temporal-spatial sequential ML algorithm.