Propagation-Loss Measurements and Modelling for Topographically Smooth and Rough Seabeds

Abstract

Acoustic propagation loss data were obtained along two radial tracks from a receiving array at a site on the Scotian Shelf. One track was over a smooth seabed and the other over a rough seabed. The features of the propagation loss data for the two seabed types have been analyzed and compared. At-sea measurements show that fluctuations in the propagation loss data are correlated with water-depth variations for the case of the rough seabed. Two different propagation-loss modelling programs are used in an attempt to explain the acoustic features observed over the two seabeds. The majority of the modelled results were obtained with PROLOS, a DREA-developed range-dependent normal-mode program. The results of a ray-trace propagation-loss model (GRASS are also compared with the measured data. The ray-trace model provides insight on which acoustic transmission paths are most important, while PROLOS is able to model the propagation-loss over both the smooth and rough seabeds surprisingly well. Keywords: Underwater acoustics; Shallow water; Hydrophone arrays; Underwater sound transmission; Marine geophysics; Continental shelves; Submarine topographic features; Surface roughness, Canada.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1989
Accession Number
ADA212376

Entities

People

  • Francine Desharnais
  • Philip R. Staal

Organizations

  • Defence Research and Development Canada

Tags

Communities of Interest

  • Ground and Sea Platforms
  • Sensors

DTIC Thesaurus Topics

  • Abstracts
  • Acoustic Propagation
  • Acoustic Properties
  • Acoustics
  • Continental Shelves
  • Experimental Data
  • Frequency
  • Frequency Bands
  • Long Wavelengths
  • Measurement
  • New York
  • Reflection
  • Seabed
  • Secondary Waves
  • Shallow Water
  • Signal Processing
  • Underwater Acoustics

Readers

  • Acoustical Oceanography.