An Experimental Investigation of Ocean Sediment Effects upon Long-Range Transmission Loss in Shallow Water.
Abstract
For many shallow-water areas, the dominant effect of the environment upon sound propagation is volume absorption in the upper sedimentary layers of the seabed. In these shallow-water areas, sound propagation is generally modeled using normal-mode theory, and, within this theory, the effects of sediment absorption are implemented through the mode-attenuation coefficients. In this study, Volume absorption was determined experimentally from mode-attenuation coefficients measured using explosive sources at sites having varied sediment types. Absorption was predicted using the sediment models of Biot and Hamilton, and compared with the experimental absorption data. Comparison between experimental and predicted absorption showed good agreement for three sites having medium-to-coarse sediments. The Biot model gave the best results for these sites and predicted a frequency dependence of f 1.76 for data obtained over frequency range of 50 to 600 Hz. The best agreement was obtained for a site having a mud bottom where the Biot model gave slightly better results than that of Hamilton over a frequency range of 25 to 250 Hz. Transmission loss was predicted for a site on the Scotian Shelf with a sloping bottom using values of sediment absorption predicted with the sediment models.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 09, 1980
- Accession Number
- ADA097207
Entities
People
- John Harold Beebe
Organizations
- Pennsylvania State University