Acoustic Propagation and Scattering in Complex Underwater Environments
Abstract
Understanding acoustic propagation and scattering in littoral and continental shelf environments is critical to sonar performance predictions for mine hunting and anti-submarine warfare. Key environmental factors affecting acoustic propagation and scattering are the ocean sediment and, in the Arctic, ice cover. Both of these factors are highly variable and include other complicating aspects such as benthic biology in the sediment, keels in the ice and patchiness and gradients in the bulk properties of the ice and sediment both in range and depth. In this project, each of these factor???s relative importance to sonar performance modeling will be considered. Finite Element models will be constructed to provide a noiseless test bed to assess each factor???s relative importance. In past efforts, these models have been either two-dimensional or pseudo-hreedimensional. In this effort, a near-field finite element model in a small domain will be constructed and extended to the far-field solution using a Green???s function approach. Domain edge effects will be avoided by using equation-based modeling. Canonical models based on this approach for scattering from spherical targets have already been calculated and compare well with analyticalsolutions. In order to assess the validity of the models, acoustic experiments will be conducted on sediment housing benthic biology in collaboration the University of Southampton, UK. Models of propagation under ice will be compared with recent measurements from the Canadian Basin Acoustic Propagation Experiment (CANAPE). Finally, reflection measurements from the Gulf coast, the U.S. East coast and the Arctic will be compared with Finite Element models.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 26, 2018
- Source ID
- N000141812591
Entities
People
- Marcia J. Isakson
Organizations
- Office of Naval Research
- United States Navy
- University of Texas at Austin