Feature-based maximum entropy for geophysical properties of the seabed

Journal of the Acoustical Society of America
By: , and 

Links

Abstract

The coherent recombination of a direct and seabed reflected path is sensitive to the geophysical properties of the seabed. The concept of feature-based inversion is used in the analysis of acoustic data collected on a vertical line array (VLA) on the New England continental shelf break in about 200 m of water. The analysis approach for the measurements is based on a ray approach in which a direct and bottom reflected path is recombined, resulting in constructive and destructive interference of the acoustic amplitudes with frequency. The acoustic features have the form of prominent nulls of the measured received levels as a function of frequency as a broadband (500–4500 Hz) source passes the closest point of approach to the VLA. The viscous grain shearing (VGS) model is employed to parameterize a two-layer seabed model. The most likely seabed is a sand sediment with a porosity of about 0.42. There is a possibility of a thin (less than 0.5 m) surface layer having a slightly higher porosity between 0.45 and 0.50. Using the estimates for the VGS parameters inferred from the short-range frequency features, a normal mode model is used to predict the received acoustic levels over larger range scales.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Feature-based maximum entropy for geophysical properties of the seabed
Series title Journal of the Acoustical Society of America
DOI 10.1121/10.0026202
Edition 3559
Volume 155
Year Published 2024
Language English
Publisher Acoustical Society of America
Contributing office(s) Woods Hole Coastal and Marine Science Center
Description 9 p.
First page 3567
Other Geospatial New England shelf break
Google Analytic Metrics Metrics page
Additional publication details