Geoacoustic inversion of ocean surface-wave noise with a littoral glider
Passive acoustics can be used to characterize the ocean bottom in a littoral environment. Ocean surface-wave noise acts as a natural directional source that can be measured to obtain bottom loss and subsequently inverted to obtain bottom density, sound speed, attenuation, and layering structure. A physical ocean surface noise model is introduced and its horizontal/vertical spatial cross-correlations discussed. Acoustical energy conservation and its relation to bottom loss are discussed. The measurement method is a continuation of the ambient noise inversion work of [J. I. Arvelo, Jr., J. Acoust. Soc. Am. 123, 679-686 (2008)]. Aggressive adaptive beamforming is used for high-resolution bottom loss measurements with surface-wave noise as a source. Ambient noise measurements with an eight-element wire polyvinylidene fluoride vertical line array mounted in the bow of a littoral glider are presented. Results from summer 2008 measurements in Port Madison, WA are presented and compared against known bottom loss curves for the area.
presented at Miami Acoustical Society meeting, 12-Nov-2008
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