DATA-MODEL COMPARISONS OF REVERBERATION AT THREE SHALLOW-WATER SITES

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Authors
  1. Desharnais, F.
  2. Ellis, D.D.
Corporate Authors
Defence Research Establishment Atlantic, Dartmouth NS (CAN)
Abstract
Reverberation measurements made by the SACLANT Undersea Research Centre at three shallow-water sites (130-190-m depth) are compared with each other and with estimates from the DREA normal-mode reverberation model OGOPOGO. The experiments over silt-clay and sand seabeds were conducted at slightly bistatic geometries (0.7-6.0-km source-receiver separation), using explosive sources detonated at mid-water depths. The signals were received on hydrophones of either a vertical or horizontal array and analyzed in one-tenth-decade frquency bands from 25 to 1000 Hz. The data are compared with each other to investigate the site differences and frequency dependencies, and with the estimates from the reverberation model OGOPOGO to interpret the data and to obtain a qualitative measure of the scattering. For modeling purposes, geoacoustic models of the seabed were assumed, and the reverberation data were fitted by adjusting the Lambert bottom scattering coefficients. Good moel agreement was obtained with both individual hydrophone and beam data. Though somewhat sensitive to the geoacoustic model, the Lambert coefficients give a measure of the frequency dependence of the scattering. For the silt-clay bottom, the scattering is weak but is independent of frequency; for the sand bottoms, the scattering is stronger and increases with frequency. These results are compared with estimates from other experiments.
Keywords
OGOPOGO;Geoacoustics
Date of publication
30 Apr 1997
Number of Pages
7
Reprinted from
IEEE Journal of Oceanic Engineering, vol 22, no 2, 1997, p 309-316
DSTKIM No
97-03516
CANDIS No
503686
Format(s):
Hardcopy;Document Image stored on Optical Disk

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