Shallow Water Acoustics
Abstract
In response to the Navy's need for a submarine warfare capability in shallow water areas of the oceans, NRL has been conducting a research program in shallow-water acoustics. The goal of the first phase of this program has been to determine if wave theory can be used to predict the acoustic field at long ranges from a submerged acoustic source. The approach used an iterative process involving trial models and at-sea measurements. The wave equation for the physical model is solved by numerical methods and implemented on a high-speed general-purpose computer. Since the acoustic field at long ranges is propagated in the discrete normal modes of the duct, special experimental methods were used to resolve individual modal fields so that their measured characteristics could be compared with predictions. This report presents a detailed description of the NRL normal-mode model in its current form and describes the experimental evaluation procedures and results. Salient features of the model include variable sound speed in the water, slowly variable water depth, statistically rough boundaries, sediment layering, and both shear-wave and compressional-wave propagation in the bottom. Although certain recognized problems remain to be solved, it has been demonstrated that the model can in most cases predict the characteristics of the signal field with sufficient accuracy to be a sueful tool in system design, performance prediction, and tactics.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 27, 1978
- Accession Number
- ADA057691
Entities
People
- F. Ingenito
- R. H. Ferris
- S. N. Wolf
- W. A. Kuperman
Organizations
- United States Naval Research Laboratory