东海PN剖面海底地形对水声环境影响研究

Research on the Impact of Seafloor Topography on the Acoustic Environment along the PN Section in the East China Sea

本文首先分析比较了常用的声场仿真算法,利用海底起伏地形下的实验数据对BELLHOP模型进行了校核和评估;其次,选择东海PN剖面典型起伏地形海域,利用OFES(OGCM for the Earth Simulator)模式数据,采用自组织神经网络方法获得海洋温度、盐度、深度和声速典型参数;最后,利用BELLHOP模型分别对假设平坦地形和真实起伏地形下的PN剖面声场传播过程进行仿真,给出了水声传播衰减数据,对比和分析了真实海洋地形对水声信道传播的影响效应。结果表明,BELLHOP 算法仿真结果与实验数据相吻合,在海底起伏地形下具有较好的适用性,可用于声传播特性的预测;对于海洋水声信道,较为复杂的海底地形会对声道轴和传输损失造成较为明显的影响;不同深度条件下,海底起伏地形造成的影响有所不同。

In this paper, some commonly used acoustic simulation models are analyzed and compared, and the BELLHOP model is checked and evaluated using the experiment data of tlie typical seafloor topography. Based on the study, tlie parameters of temperature, salinity, depth and sounding speed are obtained using the data of OFES (OGCM for the Earth Simulator) model and SOM (Selforganizing Map) method along PN section in the East China Sea. Finally, the acoustic propagation along the PN section under a hypothetical flat terrain condition and the real fluctuated seafloor topography condition are simulated using the BELLHOP model respectively, tlie underwater acoustic transmission attenuation data are given, and the effect of real seafloor topography on underwater acoustic transmission is compared and analyzed. Tlie results show tliat the simulation results of BELLHOP algorithm are consistent with the experimental data and it has good applicability in the fluctuating seafloor topography, which can lie used to predict tlie acoustic propagation characteristics. For the underwater acoustic channel, tlie complex seafloor topography has obvious influence on the channel axis and transmission loss. Tlie fluctuating topography of tlie seafloor has different effects at different depths.