利用浅海声场干涉条纹反演海底参数方法研究

浅海频散特性导致声场在距离-频率平面形成干涉条纹,该干涉条纹蕴含着声源以及海底信息。本文通过降噪、滤波等方法,提取船舶辐射噪声干涉条纹中距离域干涉准周期、波导不变量以及去扩展衰减系数(不考虑扩展损失后接收到噪声级随距离的衰减程度)三种特征量的观测值,基于无限均匀沉积层海底模型,采用简正波计算程序理论计算上述三种特征量作为拷贝,提出一种以模拟退火法作为搜索寻优策略的新的匹配反演海底参数的方法。海试数据处理结果表明,该方法反演估计所得海底密度、声速、衰减系数三参数用于浅海负跃层条件下的声场预报效果比较良好。

Geoacoustic characterization of shallow-water based on interference patterns

Multipath propagation in a shallow-water environment leads to coherent structure in the received field, both spatially and temporally. The interference structure contains the information of source and the geoacoustic parameters of the sediment. In this paper, the interference period of distance domain, waveguide invariant, and the slopes of the overall transmission loss(regardless of the cylindrical spreading) are extracted as acoustic observables after de-noising and filtering. A homogenous sediment layer model is used to compute forward estimates of the acoustic observables and the simulated annealing method is used as the search strategy. The experimental results show that the method of inversion obtained parameters can be effectively used for acoustic field prediction.