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Estimation of geoacoustic properties in the South China Sea shelf using a towed source and vertical line hydrophone array

Approved for public release, distribution is unlimited / Linear sound sweeps from a towed J15-3 sound source were collected at a moored VLA hydrophone array in the South China Sea during the ASIAEX experiment in May 2001. Measured signals were filtered and pulse compressed. The processed data showed a high signal to noise ratio. Given an a priori chirp sonar survey, a two layer bottom "first guess" model was constructed. A broadband coupled-mode model was used to perform an exhaustive frequency variant sensitivity study of VLA pressures to changes in bottom properties as a basis for the geoacoustic inverse problem. Study results provided information on the observability of the various geoacoustic parameters and a procedure for the inversion. Matched field processing of the VLA data, using the same coupledmode model, was then performed to calculate ambiguity diagrams from which geoacoustic parameter estimates were obtained. Since VLA pressure fields were not sensitive to changes in the sediment attenuation coefficient, a matched field technique that correlated the slope of modeled transmission loss to the negative slope of 10log of the observed energy was performed in order to obtain estimates of the attenuation. These estimates showed a frequency dependent attenuation coefficient in the 50-600Hz frequency band. / Lieutenant, United States Navy

Identiferoai:union.ndltd.org:nps.edu/oai:calhoun.nps.edu:10945/1217
Date12 1900
CreatorsMarburger, John M.
ContributorsChiu, Ching-Sang, Miller, Christopher, Naval Postgraduate School (U.S.)., Department of Oceanography
PublisherMonterey, California. Naval Postgraduate School
Source SetsNaval Postgraduate School
Detected LanguageEnglish
TypeThesis
Formatxii, 35 p. : ill. (some col.), col. maps, application/pdf
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. As such, it is in the public domain, and under the provisions of Title 17, United States Code, Section 105, may not be copyrighted.

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