基于深海声影区海底反射损失的地声参数反演方法

Geoacoustic parameter inversion based on seabed reflection loss in the shadow zone of deep ocean

海底的声速、密度、衰减系数等地声参数,在声场预报、目标定位中十分重要。因地声参数原位测量和海底采样在深海中实施困难,需要寻找新的方法来获取地声参数。在深海声影区环境下,直达波会随着距离的增加而逐渐消失,一次反射波及多次反射波是对深海声影区声场起重要作用的多途信号。文章首先对声影区多途达到结构进行分析,利用多次比较法得到随掠射角变化的反射损失,并对海底地声参数进行反演,然后将反演的地声参数代入声场模型得到海底反射损失,将其与实验测量结果进行比较,结果吻合较好。并通过对反演过程的散点图和后验概率进行分析,证明了反演结果的可靠性。该方法可用于深海声影区的海底地声参数的反演。

The seabed acoustic parameters such as sound velocity,density and attenuation coefficient are important in sound field forecasting and target positioning.The in-situ measurements and seafloor sampling are usually very difficult to implement in the deep ocean,and so,new methods obtaining seabed acoustic parameters need to be found.In the shadow zone of deep ocean,as the range increases,the direct wave will gradually disappear,and the reflected wave and multiple reflected waves play an important role in the sound field.In this paper,the multiple arrival structure of acoustic waves in the shadow zone is analyzed,and the seabed reflection loss varying with grazing angle is obtained by multiple comparisons,which can be used to perform geoacoustic inversion.Finally,the seabed reflection losses obtained by bringing the inversion of seabed acoustic parameters into the acoustic field model are compared with the measured ones,and both results are basically consistent.The analyses of scatter plot and marginal probability distribution in the inversion process represent the credibility of the inversion results.This method provides a feasible solution to the inversion of the seabed acoustic parameters in the shadow zone of deep ocean.