基于深海声场干涉结构的影区被动目标测距测深方法研究

Acoustic detection and localization technique is an important method to the security of the marine environment. Based on the national development strategy of “the Belt and Road”, the investigation of acoustic detection and localization technique in deep water is increasingly important. This research aims to estimate range and depth of sound source in shadow zone based on the frequency-range interference structure of sound field in deep water. In addition, this research also includes the impact of the uncertainty factors of hydrology and topography, the mutual influence between range estimate and depth estimate, the impact of the signal-to-noise ratio of received signal and the extraction of sound field interference structure in deep water. Compared with traditional passive range and depth estimation methods, the method suggested by this research doesn’t need broadband guide source, precise seafloor acoustic parameters and large scale computing of replica fields. Overall, this research work has innovation and practical application value, and has vital significance to enhance the detection performance of underwater acoustic equipment in our country.

声学探测与定位技术是海洋环境安全保障的重要手段。根据国家“一带一路”发展战略，深海声学探测与定位技术等深海声学研究日益重要。本项目拟基于深海影区声场频率-距离干涉结构，分析影区干涉结构与传播距离、收发深度之间的关系，研究对影区水面水下目标进行声学测距测深的方法。研究的内容还包括深海水文和地形的不确定性对被动测距测深的影响，声源距离估计和深度估计之间的互相影响，接收信号的信噪比对被动测距测深的影响和深海声场干涉结构提取方法。与传统被动测距测深方法相比，本项目研究方法不需要宽带引导声源、精确的海底声学参数和大规模的拷贝场计算。本项目研究内容具有创新性和实际应用价值，对于提高我国水声设备的探测能力具有重要意义。

对于深海低频声场，根据射线理论由于经多次海底反射的声线幅度较小可忽略，实际上对于声场影响较大的声线数目不多，便于分析深海声场干涉结构。本项目基于射线理论分析当声源与接收水听器位于深度较浅的表面附近时声源激发的典型深海声场频率距离干涉结构，影区内在固定距离下声场的频率干涉周期固定，即干涉条纹在频率域上等间隔分布，同时频域干涉周期随传播距离单调增加、随声源或接收深度单调减小，深海声场干涉结构携带声源距离、深度信息。. 本项目提出了一种针对水下声源，基于深海声场干涉结构的单水听器声源被动测距测深方法，通过根据海洋环境参数仿真第二种频域干涉周期、根据单水听器实测信号提取两种频域干涉周期、匹配第二种频域干涉周期估计声源距离、匹配第一种频域干涉周期估计声源深度，通过仿真和实验得到了验证，并分析了海洋环境参数的变化对于水下声源被动测距测深效果的影响，相关工作发表了论文、申请了专利。. 本项目提出了一种针对水面声源，基于深海声场干涉结构的单水听器声源被动测距方法，通过判断海面目标声场干涉结构、提取干涉周期、仿真计算干涉周期、匹配干涉周期估计声源距离，通过多次深海海上实验验证，相关工作发表了论文、申请了专利。