Physics-based Modeling of Acoustic Reverberation in the Littoral Environment

Underwater acoustic modeling plays an essential role in the design, development, test, and operation of sonar systems. Active acoustic clutter can increase the sonar false alert rate or equivalently decrease the probability of detection/classification,and is a key issue in the development and utility of active sonar systems. The ability to predict reverberation and clutter is inseparably tied to other modeling tasks, including propagation modeling as well as boundary and volume characterization. Thesystem sonar equation method supports development of a virtual acoustic environment and can be used to produce time series data for examination of the reverberation and clutter influence in the sonar system's operating parameters. A multi-tiered approachwill be used, including 1) a review of current Sonar Equation approaches to the physical modeling of reverberation and clutter, 2) a review of existing propagation models in relation to scattering problem issues, 3) a review of existing reverberation andclutter related databases, 4) a discussion of virtual modeling issues, and 5) a summary assessment of the most viable approaches. The overall objective is to develop and incorporate physics-based clutter modeling approaches into current system sonarequation and propagation models used by the sonar designer, planner, and operator. The importance of this development is that such models do not now exist and would be of paramount value to all aspects of underwater sound research from sonar design tomission planning and assessment. The model would have broad application throughout the Navy at every level from basic research to sonar design and employment. We would anticipate that it would have consideration as an OAML product. A Phase II effortwould be for further development of the model, and Phase III would be for delivery and deployment of the technology to the naval community, while exploring dual-use in the oil and gas exploration industries.