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Full-Text Articles in Engineering
Meso-Scale Seabed Quantification With Geoacoustic Inversion, Tim Sonnemann, Jan Dettmer, Charles W. Holland, Stan E. Dosso
Meso-Scale Seabed Quantification With Geoacoustic Inversion, Tim Sonnemann, Jan Dettmer, Charles W. Holland, Stan E. Dosso
Electrical and Computer Engineering Faculty Publications and Presentations
Abstract Knowledge of sub-seabed geoacoustic properties, for example depth dependent sound speed and porosity, is of importance for a variety of applications. Here, we present a semi-automated geoacoustic inversion method for autonomous underwater vehicle data that objectively adapts model inference to seabed structure. Through parallelized trans-dimensional Bayesian inference, we infer seabed properties along a 12 km survey track on the scale of about 10 cm and 50 m in the vertical and horizontal, respectively. The inferred seabed properties include sound speed, attenuation, density, and porosity as a function of depth from acoustic reflection coefficient data. Parameter uncertainties are quantified, and …
Source Level Of Wind-Generated Ambient Sound In The Oceana, N. Ross Chapman, Michael Ainslie, Martin Siderius
Source Level Of Wind-Generated Ambient Sound In The Oceana, N. Ross Chapman, Michael Ainslie, Martin Siderius
Electrical and Computer Engineering Faculty Publications and Presentations
Inference of source levels for ambient ocean sound from local wind at the sea surface requires an assumption about the nature of the sound source. Depending upon the assumptions made about the nature of the sound source, whether monopole or dipole distributions, the estimated source levels from different research groups are different by several decibels over the frequency band 10–350 Hz. This paper revisits the research issues of source level of local wind-generated sound and shows that the differences in estimated source levels can be understood through a simple analysis of the source assumptions.
Optimally Distributed Receiver Placements Versus An Environmentally Aware Source: New England Shelf Break Acoustics Signals And Noise Experiment, William K. Stevens, Martin Siderius, Matthew J. Carrier, Drew Wendeborn
Optimally Distributed Receiver Placements Versus An Environmentally Aware Source: New England Shelf Break Acoustics Signals And Noise Experiment, William K. Stevens, Martin Siderius, Matthew J. Carrier, Drew Wendeborn
Electrical and Computer Engineering Faculty Publications and Presentations
This article describes the results of the Spring of 2021 New England Shelf Break Acoustics (NESBA) Signals and Noise experiment as they pertain to the optimization of a field of passive receivers versus an environmentally aware source with end-state goals. A discrete optimization has been designed and used to demonstrate providing an acoustic system operator with actionable guidance relating to optimally distributed receiver locations and depths and likely mean source detection times and associated uncertainties as a function of source and receiver levels of environmental awareness. The uncertainties considered here are those due to the imperfect spatial and temporal sensing …
Real-Time Joint Ocean Acoustics And Circulation Modeling In The 2021 New England Shelf Break Acoustics Experiment (L), Brendan J. Decourcy, Ying-Tsong Lin, Weifeng Gordon Zhang, Emma Reeves Ozanich, Natalie Kukshtel, Martin Siderius, Glen Gawarkiewicz, Jacob Forsyth
Real-Time Joint Ocean Acoustics And Circulation Modeling In The 2021 New England Shelf Break Acoustics Experiment (L), Brendan J. Decourcy, Ying-Tsong Lin, Weifeng Gordon Zhang, Emma Reeves Ozanich, Natalie Kukshtel, Martin Siderius, Glen Gawarkiewicz, Jacob Forsyth
Electrical and Computer Engineering Faculty Publications and Presentations
During the spring of 2021, a coordinated multi-vessel effort was organized to study physical oceanography, marine geology and biology, and acoustics on the northeast United States continental shelf, as part of the New England Shelf Break Acoustics (NESBA) experiment. One scientific goal was to establish a real-time numerical model aboard the research vessel with high spatial and temporal resolution to predict the oceanography and sound propagation within the NESBA study area. The real-time forecast model performance and challenges are reported in this letter without adjustment or re-simulation after the cruise. Future research directions for post-experiment studies are also suggested.
Selected Topics Of The Past Thirty Years In Ocean Acoustics, Michael D. Collins, Altan Turgut, Michael J. Buckingham, Peter Gerstoft, Martin Siderius
Selected Topics Of The Past Thirty Years In Ocean Acoustics, Michael D. Collins, Altan Turgut, Michael J. Buckingham, Peter Gerstoft, Martin Siderius
Electrical and Computer Engineering Faculty Publications and Presentations
This paper reviews some of the highlights of selected topics in ocean acoustics during the thirty years that have passed since the founding of the Journal of Theoretical and Computational Acoustics. Advances in computational methods and computers helped to make computational ocean acoustics a vibrant area of research during that period. The parabolic equation method provides an unrivaled combination of accuracy and efficiency for propagation problems in which the bathymetry, sound speed, and other environmental parameters vary in the horizontal directions. The extension of this approach to cases involving layers that support shear waves has been an active area …
Geoacoustic Inversion Of Ship Radiated Noise In Shallow Water Using Data From A Single Hydrophone, Steven E. Crocker, Peter L. Nielsen, James H. Miller, Martin Siderius
Geoacoustic Inversion Of Ship Radiated Noise In Shallow Water Using Data From A Single Hydrophone, Steven E. Crocker, Peter L. Nielsen, James H. Miller, Martin Siderius
Electrical and Computer Engineering Faculty Publications and Presentations
The Centre for Maritime Research and Experimentation conducted a geoacoustic inverse experiment in the Mediterranean Sea in the summer of 2012. Among the objectives was to employ an autono- mous underwater vehicle to collect acoustic data to invert for properties of the seafloor. Inversion results for the compression wave speed in the bottom and the source spectrum of the R/V Alliance during a close approach to the bottom moored vehicle are presented. The estimated wave speed was 1529 m/s (r ¼ 10). The source spectrum of the Alliance was estimated across more than six octaves of frequency.