浅海海底界面混响平均强度特性仿真

海底粗糙界面是产生混响的主要因素之一。本文通过理论分析和数值仿真的方法,根据浅海全波动混响模型对不同海底粗糙界面所引起浅海混响平均强度特性进行研究,主要考虑Goff-Jordan谱、Gauss谱和指数谱三种不同粗糙界面条件下的海底反向散射强度和混响平均强度特性。计算结果表明:海底粗糙界面会引起海底反向散射强度的频率特性的差异,进而导致海底平均混响强度的频率特性的差异,但随入射角度的变化不大。即使界面起伏的方差和相关长度相同,不同的粗糙度谱也会引起平均混响强度的差异。

Simulations of the average reverberation intensity due to different rough bottom interfaces in shallow-water waveguide

The bottom rough interface is one of the main factors which cause reverberation in shallow water waveguide. The numerical simulation and theoretical derivation of the average intensity of reverberation due to interface roughness have been performed based on full wave reverberation theory in this paper. Roughness spectrum is used to describe different bottom rough surface. Three common roughness spectrums have been considered in the simulation, Goff-Jordan spectrum, Exponential spectrum and Gaussian spectrum. The characteristics of bottom backscattering strength and the average reverberation intensity due to different bottom roughness spectrums have been calculated. The result shows that: different bottom rough surfaces can cause the frequency dependency and angular dependency of bottom backscattering strength. Further, it can cause the frequency dependency of average reverberation intensity. Different roughness spectrum with the same rootSmeanSsquare (RMS) and correlation length can causes the change in average reverberation intensity.