Accession Number:

ADA175540

Title:

The Influence of Bubbles on Sea Surface Backscatter Measurements (Der Einfluss von Blasen auf die Messung der Rueckstreueigenschaften der Meeresoberflaeche).

Descriptive Note:

Technical document,

Corporate Author:

NAVAL UNDERWATER SYSTEMS CENTER NEWPORT RI

Report Date:

1986-10-26

Pagination or Media Count:

26.0

Abstract:

Results from a recent sea surface acoustic scattering experiment, conducted in the North Sea, are presented with accompanying sea surface roughness parameters and subsurface bubble information. The acoustic data were obtained using a high resolution narrow beamwidth pulsed parametric sonar transmitter and conventional receiver. Scattering strength values were obtained as a function of frequency 3-18 kHz for wind speeds from 2 to 45 knots. It appears that the backscattering strength at a 30 deg grazing angle is caused by the high frequency wavenumber spectrum at low wind speeds and by sub-surface bubbles at high wind speeds. The backscattering strength shows strong fluctuations in the intermediate region caused by both scattering mechanisms. Keywords Ocean waves Parametric sonar Radar backscatter Reverberation Surface roughness dependence Shallow water Wave height dependence Wind dependence Acoustic scattering strenth Frequency dependence Grazing angle Dependence.

Subject Categories:

  • Acoustic Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE