基于改进子空间投影的无源雷达弱目标检测方法

摘要

基于子空间投影的无源雷达弱目标检测方法是将回波通道接收信号投影到与多径干扰子空间和强目标子空间均正交的子空间内,需要构造的投影矩阵维数过大,导致计算量很大.为了解决这一问题,利用多次小维数投影代替大维数投影,提出了一种改进的无源雷达弱目标检测方法.首先将接收信号投影到多径干扰的正交补子空间内,然后连续地将信号投影到强目标的正交补子空间内,最终达到干扰抑制和弱目标检测的目的.本方法可以有效抑制多径、强目标干扰,在保持检测性能的同时大幅度降低计算量,提高了方法的实时性.仿真结果表明了方法的有效性.%The subspace projection approach is used for interference suppression and weak target detection in passive radar systems. The signal received in the echo channel is projected onto the subspace orthogonal to both multi-path interference and strong targets subspace. With this method, the computational load is very high due to the large size of the projection matrix. To reduce the computational load, an improved weak target detection method which replaces the large size projection matrix with several small size projection matrices is introduced. First, the signal received in the echo channel is projected onto the orthogonal complement of multi-path interference subspace. Then it is continuously projected onto the orthogonal complement of strong targets subspace. With respect to the subspace projection approach, the improved approach performances comparable capability in both interference suppression and weak target detection with computational simplicity. Finally its effectiveness is illuminated by simulation results.