Propagation Loss Model Assessment at Low Frequencies in a Bottom-Limited Region
Abstract
A physical insight into the problem of low frequency propagation loss modeling in a bottom-limited region is gained by comparison of a representative range of prediction models with a precisely determined set of experimental data. One series of the Project BILL(Below and In Layer Propagation Loss) measurements was conducted at 100 Hz during December 1973 in the Tongue of the Ocean, Bahama Islands, at a water depth of approximately 1800 meters. A pulsed CW acoustic projector was towed at a depth of 76 meters along an accurately determined track to a range of 40 kiloyards. The pulses were received at hydrophones located both in and below the surface duct. Despite excellent experimental control, predictions from various propagation loss models have been unable to reproduce major features of the multipath interference structure of the data. Although few firm conclusions are possible, the report discusses several possible contributory causes for the discrepancies, major among these being inadequate bottom modeling. Implications for future trends in the development of low frequency propagation loss models for bottom-limited regions are briefly examined.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 30, 1976
- Accession Number
- ADA027354
Entities
People
- Frederick R. Dinapoli
- Grant Gartrell
Organizations
- Naval Undersea Warfare Center