Downslope Propagation and vertical Directionality of Wind Noise
Abstract
Measurements of the vertical noise intensity versus angle W. Carey and R. Wagstaff, J. Acoust. Soc. Am. 80, 1523-1526 (1986) show the low-frequency distribution (<200 Hz) to be broadly peaked about the horizontal, whereas the higher-frequency (approx. 400Hz) distribution is peaked at the SOFAR angles (approx. + or - 15 deg.) near the axis with a minima at the horizontal. This effect has been attributed to the noise from ships over the basin margins R. Wagstaff, J. Acoust. Soc. Am. 69, 1009-1014 (1981) has attributed this effect to high-latitude winds and shallowing sound channel found in Southern Hemisphere waters. W. Carey J. Acoust. Soc. Am. 79, 49-59 (1986) attributed the effect to downslope propagation. Calculations between 50 and 400 Hz of the mid-basin vertical directionality made with ASTRAL and PAREQ with a geoacoustic model were both found to show that the bottom behaves as a low-pass filter as the low- frequency energy at higher angles interacts with the bottom and is converted to low-angle energy in the deep sound channel while, at the higher frequencies and higher angle, energy is absorbed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 24, 1987
- Accession Number
- ADA205996
Entities
People
- George Botseas
- J. Davis
- R. B. Evans
- William M. Carey
Organizations
- Naval Underwater Systems Center