The Influence of Bubbles on Sea Surface Backscatter Measurements (Der Einfluss von Blasen auf die Messung der Rueckstreueigenschaften der Meeresoberflaeche).
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 26, 1986
- Accession Number
- ADA175540
Entities
People
- Bernd Nuetzel
- Heinz Herwig
- Joseph M. Monti
- Paul D. Koenigs
Organizations
- Naval Underwater Systems Center