非完全深海声道环境下混响强度建模与分析

Modeling and analysis of reverberation intensity in incomplete SOFAR channel

为研究非完全深海声道环境下海面和海底近距离大掠射角散射以及远距离小掠射角散射对混响的贡献,本文采用小斜率近似考虑全掠射角范围粗糙界面散射作用,结合射线理论声场算法,建立了海面和海底混响强度模型。利用南海实测混响数据对模型进行了验证,通过数值计算比较了海面和海底混响强度衰减特性差异,揭示了不同时间段的混响信号多途属性。结果表明:在表面声速为负梯度的非完全深海声道环境中,对于通常的海面附近发射和接收情形,海面混响强度衰减较快,海底散射起主导作用。

To study the contribution of scattering energy of surface and bottom roughness to reverberation at both large grazing angle and small grazing angle in an incomplete sound fixing and ranging channel,a model of surface and bottom reverberation intensity is proposed in this paper based on ray theory.The small-slope approximation is applied to computing the roughness-scattering intensity over a wide range of angles.The proposed model is verified through comparison with experimental data collected from the South China Sea.Differences in reverberation intensity between surface and bottom are compared according to numerical calculations,and the multipath characteristics of the reverberation signal are also revealed.Analytical results indicate that in incomplete deep-water sound channel,reverberation produced by a near-surface source or receiver is mainly influenced by bottom roughness scattering,and the decaying rate of surface reverberation is relatively fast.