Estimation of geoacoustic properties in the South China Sea shelf using a towed source and vertical line hydrophone array
Marburger, John M.
MetadataShow full item record
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.
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
Null, James Mark. (Monterey, California. Naval Postgraduate School, 1995-03);In many strategic shallow water areas the geoacoustic properties of the sub-bottom are largely unknown. In this thesis it is demonstrated that inverse theory and measured data from a single hydrophone can be used to ...
Howell, Henry R. G. (Monterey, California. Naval Postgraduate School, 2000-09);Inversion techniques are used to infer bottom geoacoustic properties using AN/SQQ-32 Reverberation Level (RL) data gathered by USS Avenger (MCM-1) in Rhode Island Sound in February 1993. Based on the hypothesis that the ...
Duarte, Steven P. (Monterey, California. Naval Postgraduate School, 1994-12);Project GEMINI was initiated to study the sound pressure fields in a range-independent, benign shallow water environment. The project consisted of five separate experiments conducted at a shallow site (approx. 20 m), a ...