时间反转-逆时偏移混合法用于超声在分层介质和水下波导中目标的探测和定位

项目名称： 时间反转-逆时偏移混合法用于超声在分层介质和水下波导中目标的探测和定位

项目编号： No.11474304

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 汪承灏

作者单位： 中国科学院声学研究所

项目金额： 87万元

中文摘要： 对于分层介质和水下波导，由于存在界面的干扰，一般声学检测方法检测其中的目标或缺陷常常失效。但是这些检测问题有很重要的应用背景。它们包括分层介质中在界面附近的缺陷的超声检测，多层介质中界面脱粘区和缺陷的超声检测，海底下的目标水声探测以及主动声纳对具有混响海底的浅海波导中目标的探测等，为了解决这些问题，本项目提出时间反转和逆时偏移混合方法，它能消除界面的影响，实现分层介质中缺陷和水下波导中目标的检测和定位。本项目将分别从理论分析，实验和数据处理三个方面进行研究。理论分析和数据处理将采用Kirchhoff射线跟踪和互相关两种方法。而实验所用的分层介质界面为流体-流体，流体-固体和固体-固体三类，水下波导实验是在消声水槽中进行的，其底面分别为刚性底，吸收底和混响底三类。通过本项目的研究为这些重要的声学检测问题的解决提供了一定的物理基础。

中文关键词： 超声检测；时间反转；逆时偏移；分层介质；波导

英文摘要： By using general acoustic detection methods, due to disturbance of interface,detecting the flaw in layered media and the target in underwater waveguide which have very important applied background would lose the efficiency often. These important applications involve: ultrasonic detection of flaws near interface in layered medium，ultrasonic detection of debonding areas between interfaces and flaws in multilayered medium; acoustic detection of target under sea bottom and active echo ranging in shallow water with bottom reverberation. In order to solving these acoustic detection problems, the project suggests time reversal (TR)-reverse time migration (RTM)mixed method which may eliminate the influence of interface and detect successfully the targets in underwater waveguide and the flaws in layered medium .This project will be carried out by using theoretical analysis , experimental research and data process. In theoretical analysis and data process, both Kirchhoff's ray tracing and cross-correlation methods will be adopted. In experiments, the layered media are divided into three kinds: fluid-fluid, fluid-solid and solid-solid interfaces. And the experiments of underwater waveguide would be in an anechoic water bath which has three types of rigid, absorbed and reverberation bottoms. Physical foundations of solving these important acoustic detection problems will be laid through this project research.

英文关键词： Ultrasonic test;Time reversal;Reverse time migration;layered medium;waveguide