深海会聚区目标强度特性分析

深海中当声源位于海表面附近时，在远离声源处会形成高声强焦散的会聚区。在现代水声技术应用中，可以利用水下声道中的会聚区来实现深海目标的远程探测。本文对会聚区的形成条件和会聚区目标相对声强的特性进行分析，结果表明：只有当声速极小值存在并且声线出射角满足一定条件时才会形成会聚区效应；会聚区中相对声强水平分布具有双峰结构；当接收深度与目标深度相同时相对声强会出现峰值，这为深海目标的深度判定提供了一种方法。

Analysis of the target sound intensity characteristic in the deep ocean

When the sound source is located near the surface in the deep ocean, there will be strong caustics conver-gence zone far away from the sound source. In modern underwater acoustic technology applicationwe can use the underwa-ter channels convergence zone to achieve the goal of long-range detection of target in the deep ocean. In this paper, we ana-lysis the formation conditions of convergence zones and the target relative sound intensity characteristic in convergence zones, the results shows:only when the minimum speed of sound exist and the exit angle of ray satisfies certain conditions can there be a convergence zone effect. Relative sound intensity level distribution has a bimodal structure in the convergence zone. When the receiving depth and the target depth are of the same, the relative sound intensity peak appears, and this provides a method for determining the depth of the deep target.