Identification of objects in an acoustic waveguide: numerical results and an introduction to an alternate approach via the method of images
University of Delaware
This thesis discusses the problem of the localization and identification of three-dimensional objects in a shallow water waveguide. This problem is an inverse problem. The observed data is the total wave field surrounding the body whose shape is to be reconstructed. The method involves using sound as an incident wave that will be scattered by the unknown body to create a scattered wave field. The problem is then solved by an inversion of the scattered wave-field. A least-squares matching of theoretical acoustic fields against the measured scattered field permits a reconstruction of the unknown object. A major portion of this project is the numerical results presented. Measurements involving the incident and scattered field are taken on a straight line on a plane above the unknown body, but below the top boundary of the waveguide. In the final chapter, we introduce an alternative route via the method of images. Our hope is that with this latter route, we can avoid some hardly scrutable mathematical tools we have used thus far.