Accession Number:

AD1005153

Title:

High-Frequency Acoustic Scattering and Absorption Effects within Ship Wakes

Descriptive Note:

Technical Report

Corporate Author:

Defence R and D Canada Atlantic Dartmouth, Nova Scotia Canada

Personal Author(s):

Report Date:

2005-08-22

Pagination or Media Count:

8.0

Abstract:

Clouds of small air-bubbles injected and mixed into the near-surface ocean within vessel wakes can create significant acoustic scattering and extinction. Recent high frequency 100 kHz sidescan sonar measurements on a moving vessel showed persistent strong backscatter features and significant dropouts in sea-surface reverberation behind the wakes. Details of the sonar measurements and features of ship wakes recorded during these sonar trials are reviewed. Estimates of typical wake width, persistence, backscatter strength, and effective extinction are presented for the case of straight-running and turning vessels at speeds up to 20 knots.

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE