浅海环境噪声垂直指向性探测海底参数

浅海环境噪声垂直指向性和海底地声参数密切相关,可以利用它来反演海底参数。本文在水平分层介质噪声场模型下,讨论了海底参数对噪声垂直指向性的敏感度,并假设半无限大液态海底,采用效率较高的自适应单纯形模拟退火算法全局寻优,根据中国某海区实测噪声数据,估计了海底声速、密度及衰减,分析了反演结果的不确定性。鉴于声速和密度在不同频率的反演结果不够一致,文中提出多频海底参数联合反演方法,提高了反演海底声学参数的精度。

Geo-acoustic surveying for seabed parameters using vertical directionality of ambient noise in shallow water

The vertical directionality of ambient noise is influenced primarily by geo-acoustic properties of the seabed in shallow water,therefore,geo-acoustic parameters can be inferred from noise inversion.In this paper,a normal-mode model of ambient noise in range-independent environment is developed,and the sensitivities of seabed parameters to the noise vertical directionality are examined.An efficient optimization algorithm named "adaptive simplex simulated annealing" is used,and the sound speed,density and attenuation are estimated from ambient noise data measured in a shallow water area in China,assumed a homogenous half-space.The uncertainty analysis is also discussed.It is found that the sound speeds and densities are not consistent at different frequencies.In order to solve this problem,a multi-frequency inversion approach using noise vertical directionality is proposed.As a result,the precision of inversion results is developed.