一种基于压缩感知的水下目标被动测距方法

基于目标空间域的稀疏性和聚焦波束形成的机理，提出了一种基于压缩感知的水下目标被动测距方法.首先，按照先方向后距离的方法对整个搜索空间进行网格划分；其次，根据球面波传播的均匀线列阵声纳接收数据模型，针对空间每个搜索方向按均匀距离间隔构造了每个方向上完备的阵列流形，并将其作为对应方向上压缩感知的感知矩阵，结合压缩感知理论数学模型，构建了对应方向上水下目标信号估计的凸优化模型；再次，采用基追踪算法对凸优化模型进行求解，计算出每个搜索方向、距离上目标信号的能量；最后，通过搜索整个空间的信号能量峰值，实现了水下目标被动测向与测距.仿真分析表明，该方法在距离估计上具有较高的聚焦性，可有效解决传统聚焦波束形成技术距离分辨率低的问题，能够实现对水下多个互不相干窄带目标信号的被动测向和测距.

Method of Underwater Target Passive Ranging Based on Compressed Sensing

We propose a method of underwater target passive ranging based on the sparsity of the target space and the mechanism of focused beamforming. First, we mesh the distribution space of the signal sources according to the method of forward distance and backward distance. Second, we establish the model of received data with uniform linear array based on a spherical wave propagation. For each direction in space, we construct a complete array manifold matrix as a sensing matrix at uniform distance, and construct a convex optimization model for the underwater target signal estimation in the corresponding direction based on the compressed sensing theory. Third, we use a basis pursuit algorithm to solve the convex optimization model, and estimate the energy of the target signal in each direction and distance. Finally, we find the passive direction and the range of underwater target by searching the peak signal energy in the whole space. The simulation results show that the proposed method achieves a high focusing efficiency in range estimation and can effectively solve the problem of low range resolution of the conventional focused beamforming technology; moreover, it can find the passive directions and ranges of multiple independent narrowband underwater targets.