浅海波导中水平接收阵被动时反混响抑制方法研究

使用基于射线简正波异地混响理论建立的水平接收阵接收海底混响模型,提出了水平阵被动时反混响抑制方法。以水平接收阵接收回波信号的某一时刻作为开始,分别对其前一时刻和后一时刻的回波信号做时反算子分解获得两个混响子空间,将这两个混响子空间的平均作为该时刻的混响子空间的一个估计,然后利用投影处理来抑制该时刻接收信号中的混响成分。该方法可以在一定程度上克服由于海底粗糙引起的局部时间(距离)段内接收回波信号的不平稳性,使得估计得到的混响子空间更加接近真实混响子空间。因此,利用其进行被动时反混响抑制可以增强回波信混比,提高对目标的检测和方位估计能力。针对典型浅海波导环境开展的仿真验证了本文方法的有效性。

Passive reverberation nulling and echo enhancement with horizontal receiver array in shallow water

Shallow water bottom reverberation ray normal:node bistatic reverberation theory model of horizontal receiver array (HRA) was established based on the Then, a passive reverberation hulling method based on averaging of forward and backward reverberation subspace was proposed in this paper. The estimated reverberation subspace of a time-windowed segment of data received by HRA can be obtained by averaging the reverberation subspaces that are obtained by DORT method and corresponding to the previous and latter time segment respectively. The reverberation component of the current time-windowed segment data can be suppressed by the projection approach using the estimated reverberation subspace. This method can overcome the non-stationary of the received echo in local time (range) caused by the roughness of the bottom, and the estimated reverberation subspace is closer to the real one. The signal to reverberation ratio of the received echo is enhanced. As a result, the detection and bearing estimation performance is improved. The performance of proposed method was testified by numerical simulations in typical shallow water environment.