一种浅海连续声信号简正波分离方法  

Method for separating normal modes of continuous acoustic signals in shallow water waveguides

作　　者：杜思奇 韩东[2] 李思迪 DU Siqi;HAN Dong;LI Sidi(Midshipmen Group Five,Dalian Navy Academy,Dalian 116018,China;Department of Information Operation,Dalian Naval Academy,Dalian 116018,China)

机构地区：[1]海军大连舰艇学院学员五大队,辽宁大连116018 [2]海军大连舰艇学院信息系统系,辽宁大连116018

出　　处：《舰船科学技术》2025年第8期107-113,共7页Ship Science and Technology

摘　　要：针对宽带连续声信号简正波模态混叠问题,提出了一种基于水听器阵列的目标方位估计与频率-波数(Frequency-Wavenumber,F-K)变换相结合的简正波分离方法,通过设置海底水平线列阵接收目标连续声信号,利用阵列先行对目标方位进行搜索估计,根据得到的目标方位角计算信号到达各阵元的时延,并对阵列接收到的时间-距离二维信号矩阵进行时间修正,通过F-K变换将修正后的信号从时间-距离域转换至频率-波数域,在频率-波数域内实现连续声信号简正波各阶模态的分离。仿真实验验证了时频分析方法的局限性以及所提出方法的可行性,按照声源特征设置满足F-K变换频率域分辨率和波数域分辨率要求的海底水平线列阵。该方法可在声速恒定波导和实测浅海波导信噪比大于5 d B的条件下,分离距阵列20 km处目标100~200 Hz宽带声信号持续10 s以内简正波的各阶模态。To address the issue of mode aliasing in broadband continuous acoustic signals,a method for separating normal modes based on a hydrophone array for target direction estimation combined with Frequency-Wavenumber(F-K) transformation has been proposed.This method involves deploying a horizontal line array on the seabed to receive continuous acoustic signals from the target.The array first searches for and estimates the target's direction.Using the estimated azimuth angle,the time delays of the signals arriving at each array element are computed.The time domain matrix of the received time-distance signals is then corrected,and the corrected signals are transformed from the time-distance domain to the frequency-wavenumber domain using F-K transformation.In the frequency-wavenumber domain,separation of the various modes of the continuous acoustic signal is achieved.Simulation experiments validate the limitations of time-frequency analysis methods and demonstrate the feasibility of the proposed approach.A horizontal line array on the seabed is configured according to the characteristics of the sound source to meet the resolution requirements for the frequency and wavenumber domains during F-K transformation.This method can effectively separate the normal modes of broadband acoustic signals in the frequency range of 100-200 Hz,received from a target located 20 km from the array,for durations of up to 10 seconds,under conditions of constant sound speed in a waveguide and signal-to-noise ratios greater than 5 dB in measured shallowwater waveguides.

关 键 词：简正波 模态分离 方位估计 F-K变换 

分 类 号：TB565.1[交通运输工程—水声工程]