Physical Modeling of Sound Shadowing by Seamounts.
Abstract
Propagation loss due to shadowing by seamounts is studied utilizing physical models in air. Dickens Seamount in the Gulf of Alaska is approximated by three models; A plane wedge, a contoured wedge, and a scaled three dimensional model. The forward diffraction over each is analyzed for a five octave frequency range. A new concept, the far-field 'diffraction scattering strength' is defined and used to predict frequency-dependent diffraction loss at sea. The total propagation loss is calculated by adding laboratory model values of upslope forward scatter and crest diffraction losses to computer-predicted ray refraction losses up to and away from the seamount. This predicted loss is then compared to long range ocean propagation loss measurements for the case in which rays are completely blocked by the Seamount. Close agreement is found. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1979
- Accession Number
- ADA081076
Entities
People
- Robert Parish Spaudling Jr
Organizations
- Naval Postgraduate School