Underwater acoustic propagation modelling techniques : theory, operation and comparison

Abstract

Underwater acoustic signals are used for many diverse purposes ranging from pure research to anti-submarine warfare. The successful exploitation of a propagation model requires a user who is familiar with both the underlying theory and the details of the particular model. The underwater acoustic propagation modelling problem is presented in three parts. First, the theory supporting several different propagation modelling techniques is presented in a clear, detailed and logical manner. In the second part, the development of an Integrated Multi-model Acoustic Propagation Prediction System (IMAPPS) is described. The IMAPPS provides a 'user friendly' interface to the models and employs a 'state of the art' graphics display package. In the third part of the thesis, the results from using IMAPPS to conduct a number of intermodel comparisons under a variety of acoustic scenarios are presented. This study identifies a significant problem with the traditional method of displaying transmission loss data. An alternative method, based on spatial averaging, is presented and shown to produce an operationally more usable, realistic and stable product than that produced by the more traditional method. The graphical display approach developed for IMAPPS rapidly and vividly communicates the essential information about the propagation environment to the user.