浅海远程海底混响的空间相关特性分析

摘要

A shallow water waveguide is a complex reverberation-limited environment for an active sonar system because of its irregular bottom interface, strong sea floor scattering, and waveguide effects. It is important to understand the spatial correlation of long range bottom reverberation for active detection in shallow water. The bottom reverberation was considered to be the interaction of the incident field with the sea floor interface. The spatial correlation was evaluated as a function of the receiving position, time , and frequency by the couple mode reverberation theory. Calculations of vertical correlation show good agreement with the experimental data, and can he compared with horizontal correlations. The results show that transverse correlation is greater than the longitudinal correlation, and it is the most uncorrelated in vertical space.%浅海环境中,海底地形复杂且散射强度大,加之波导效应明显,因此有效地掌握浅海低频海底混响的空间分布特性对工作在浅海的主动远程探测系统极为重要.以耦合简正波理论为出发点,把海底混响视为界面不规则起伏对入射声场的耦合作用所致.依据浅海混响的耦合简正波模型,分别计算了远程海底混响的垂向、水平纵向、水平横向相关性随收发位置、时间和频率的变化关系.利用实验数据验证了该理论得到的垂向相关的计算结果,并通过理论仿真比较了垂向、水平纵向、水平横向的相关特性.研究结果表明,对于低频远程海底混响水平横向相关大于水平纵向相关,垂向的相关特性最差.