基于均匀圆阵的简正波模态分解

Normal Mode Decomposition Based on Uniform Circular Array

摘要: 浅海波导海洋环境复杂，声波往往以简正波的形式进行传播。简正波的模态分离对于浅海波导中的目标探测与定位有着重要的意义。由于线阵在做模态分离时有着很大的局限性，本文结合简正波的传播特性基于均匀圆阵提出了一种简正波模态分离方法。首先应用圆阵对目标方位进行估计，结合方位信息利用模态域波束形成原理，做波数域上的波束形成，得到各阶简正波的模态强度并实现波数域上的模态分离。本文从理论上推导了圆阵上的模态域波束形成以及模态分离的过程，并用仿真对圆阵的模态分离方法进行了验证。仿真结果表明：该算法无需海洋环境条件作为先验知识，即可在波数域对模态进行分离，并能对水平波数做出较为准确的估计。

Abstract: Shallow sea waveguide has complicated marine environment. Sound waves often propagate in a simple form. Modal separation of Normal mode is very important for target detection and location in shallow sea waveguides. The linear array in the modal separation has great limitation. Combined with the propagation characteristics of normalmodes, the separation method which is based on uniform circular array of a normal mode is proposed. Firstly, the target position is estimated by using circular array, and the modal intensity of each order Normal mode is obtained by combining the azimuth information and the beamforming principle of mode domain, do the beam forming on the beam domain and the modal separation is achieved. In this paper, we use the beamforming theory of modal domain on a circular array, and the results are verified by simulation. Simulation results show that the algorithm, without marine environment conditions as a priori knowledge, can separate the modal and estimate the horizontal wavenumber.