Acoustic Sources Of Opportunity In The Marine Environment Applied To Source Localization And Ocean Sensing
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Acoustic Sources Of Opportunity In The Marine Environment Applied To Source Localization And Ocean Sensing
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Author : Christopher M. Verlinden
language : en
Publisher:
Release Date : 2017
Acoustic Sources Of Opportunity In The Marine Environment Applied To Source Localization And Ocean Sensing written by Christopher M. Verlinden and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017 with categories.
Controlled acoustic sources have typically been used for imaging the ocean. These sources can either be used to locate objects or characterize the ocean environment. The processing involves signal extraction in the presence of ambient noise, with shipping being a major component of the latter. With the advent of the Automatic Identification System (AIS) which provides accurate locations of all large commercial vessels, these major noise sources can be converted from nuisance to beacons or sources of opportunity for the purpose of studying the ocean. The source localization method presented here is similar to traditional matched field processing, but differs in that libraries of data-derived measured replicas are used in place of modeled replicas. In order to account for differing source spectra between library and target vessels, cross-correlation functions are compared instead of comparing acoustic signals directly. The library of measured cross-correlation function replicas is extrapolated using waveguide invariant theory to fill gaps between ship tracks, fully populating the search grid with estimated replicas allowing for continuous tracking. In addition to source localization, two ocean sensing techniques are discussed in this dissertation. The feasibility of estimating ocean sound speed and temperature structure, using ship noise across a drifting volumetric array of hydrophones suspended beneath buoys, in a shallow water marine environment is investigated. Using the attenuation of acoustic energy along eigenray paths to invert for ocean properties such as temperature, salinity, and pH is also explored. In each of these cases, the theory is developed, tested using numerical simulations, and validated with data from acoustic field experiments.
Noisy Oceans
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Author : Gaye Bayrakci
language : en
Publisher: John Wiley & Sons
Release Date : 2023-12-19
Noisy Oceans written by Gaye Bayrakci and has been published by John Wiley & Sons this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023-12-19 with Science categories.
Noisy Oceans Measuring devices such as ocean bottom seismometers and hydrophones designed to detect earthquakes pick up many other signals. These were previously ignored as background noise from unknown sources, but advanced technology now allows insights into the noise created from icebergs, ships, hydrothermal vents, whales, rain, marine engineering, and more. Noisy Oceans: Monitoring Seismic and Acoustic Signals in the Marine Environment is a comprehensive guide to non-tectonic marine noise originating from different environmental, biological, and anthropogenic sources. Volume highlights include: Overview of marine soundscapes and their sources Existing and new methods for studying acoustic signals Case studies from around the world Spans disciplines from geology and geophysicists to biology Explores the impacts and implications of marine noise The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.
Machine Learning In Passive Ocean Acoustics For Localizing And Characterizing Events
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Author : Emma Ozanich
language : en
Publisher:
Release Date : 2020
Machine Learning In Passive Ocean Acoustics For Localizing And Characterizing Events written by Emma Ozanich and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020 with categories.
Passive acoustics, or the recording of pressure signals from uncontrolled sound sources, is a powerful tool for monitoring man-made and natural sounds in the ocean. Passive acoustics can be used to detect changes in physical processes within the environment, study behavior and movement of marine animals, or observe presence and motion of ocean vessels and vehicles. Advances in ocean instrumentation and data storage have improved the availability and quality of ambient noise recordings, but there is an ongoing effort to improve signal processing algorithms for extracting useful information from the ambient noise. This dissertation uses machine learning as a framework to address problems in underwater passive acoustic signal processing. Statistical learning has been used for decades, but machine learning has recently gained popularity due to the exponential growth of data and its ability to capitalize on these data with efficient GPU computation. The chapters within this dissertation cover two types of problems: characterization and classification of ambient noise, and localization of passive acoustic sources. First, ambient noise in the eastern Arctic was studied from April to September 2013 using a vertical hydrophone array as it drifted from near the North Pole to north of Fram Strait. Median power spectral estimates and empirical probability density functions (PDFs) along the array transit show a change in the ambient noise levels corresponding to seismic survey airgun occurrence and received level at low frequencies and transient ice noises at high frequencies. Noise contributors were manually identified and included broadband and tonal ice noises, bowhead whale calling, seismic airgun surveys, and earthquake T phases. The bowhead whale or whales detected were believed to belong to the endangered Spitsbergen population and were recorded when the array was as far north as 86°24'N. Then, ambient noise recorded in a Hawaiian coral reef was analyzed for classification of whale song and fish calls. Using automatically detected acoustic events, two clustering processes were proposed: clustering handpicked acoustic metrics using unsupervised methods, and deep embedded clustering (DEC) to learn latent features and clusters from fixed-length power spectrograms. When compared on simulated signals of fish calls and whale song, the unsupervised clustering methods were confounded by overlap in the handpicked features while DEC identified clusters with fish calls, whale song, and events with simultaneous fish calls and whale song. Both clustering approaches were applied to recordings from directional autonomous seafloor acoustic recorder (DASAR) sensors on a Hawaiian coral reef in February 2020. Next, source localization in ocean acoustics was posed as a machine learning problem in which data-driven methods learned source ranges or direction-of-arrival directly from observed acoustic data. The pressure received by a vertical linear array was preprocessed by constructing a normalized sample covariance matrix (SCM) and used as the input for three machine learning methods: feed-forward neural networks (FNN), support vector machines (SVM) and random forests (RF). The FNN, SVM, RF and conventional matched-field processing were applied to recordings from ships in the Noise09 experiment to demonstrate the potential of machine learning for underwater source localization. The source localization problem was extended by examining the relationship between conventional beamforming and linear supervised learning. Then, a nonlinear deep feedforward neural network (FNN) was developed for direction-of-arrival (DOA) estimation for two-source DOA and for K-source DOA, where K is unknown. With multiple snapshots, K-source FNN achieved resolution and accuracy similar to Multiple Signal Classification (MUSIC) and SBL for an unknown number of sources. The practicality of the deep FNN model was demonstrated on ships in the Swellex96 experimental data.
Acoustic Source Localization
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Author : Nilu Zhao
language : en
Publisher:
Release Date : 2016
Acoustic Source Localization written by Nilu Zhao and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
Many technologies rely on underwater acoustics. Most of these applications are able to denoise Gaussian noise from the surrounding, but have trouble removing impulse like noises. One source of impulse-like noise is the snapping shrimps. The acoustic signals they emit from snapping their claws hinder technologies, but can also be used as a source of ambient noise illumination due to the rough uniformity in their spatial distribution. Understanding the spatial distributions of these acoustic signals can be useful in working to mitigate or amplify their effects. Our collaborators in Singapore use a multi-array sensor to take measurements of the sound pressures of the environment in the ocean. This thesis investigates in solving the signal reconstruction problem -- given the measurements, reconstruct the locations of the original signal sources. A numerical model for the system consisting of the snapping shrimp signals, the environment, and the sensor is formulated. Three methods of reconstruction -- Disciplined Convex Programming, Orthogonal Matching Pursuit, and Compressive Sensing -- are explored, and their robustness to noise, and sparsity are examined in simulation. Results show that Two-Step Iterative Shrinkage Threshold (TwIST) is the most robust to noisy and non-sparse signals. The three methods were then tested on real data set, in which OMP and TwIST showed promising consistency in their results, while CVX was unable to converge. Since there is no available information on ground truth, the consistency is a promising result.
Ocean Noise And Marine Mammals
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Author : National Research Council
language : en
Publisher: National Academies Press
Release Date : 2003-05-22
Ocean Noise And Marine Mammals written by National Research Council and has been published by National Academies Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2003-05-22 with Science categories.
For the 119 species of marine mammals, as well as for some other aquatic animals, sound is the primary means of learning about the environment and of communicating, navigating, and foraging. The possibility that human-generated noise could harm marine mammals or significantly interfere with their normal activities is an issue of increasing concern. Noise and its potential impacts have been regulated since the passage of the Marine Mammal Protection Act of 1972. Public awareness of the issue escalated in 1990s when researchers began using high-intensity sound to measure ocean climate changes. More recently, the stranding of beaked whales in proximity to Navy sonar use has again put the issue in the spotlight. Ocean Noise and Marine Mammals reviews sources of noise in the ocean environment, what is known of the responses of marine mammals to acoustic disturbance, and what models exist for describing ocean noise and marine mammal responses. Recommendations are made for future data gathering efforts, studies of marine mammal behavior and physiology, and modeling efforts necessary to determine what the long- and short-term impacts of ocean noise on marine mammals.
Challenges And Innovations In Ocean In Situ Sensors
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Author : Eric Delory
language : en
Publisher: Elsevier
Release Date : 2018-09-21
Challenges And Innovations In Ocean In Situ Sensors written by Eric Delory and has been published by Elsevier this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018-09-21 with Technology & Engineering categories.
Challenges and Innovations in Ocean In-Situ Sensors: Measuring Inner Ocean Processes and Health in the Digital Age highlights collaborations of industry and academia in identifying the key challenges and solutions related to ocean observations. A new generation of sensors is presented that addresses the need for higher reliability (e.g. against biofouling), better integration on platforms in terms of size and communication, and data flow across domains (in-situ, space, etc.). Several developments are showcased using a broad diversity of measuring techniques and technologies. Chapters address different sensors and approaches for measurements, including applications, quality monitoring and initiatives that will guide the need for monitoring. Integrates information across key marine and maritime sectors and supports regional policy requirements on monitoring programs Offers tactics for enabling early detection and more effective monitoring of the marine environment and implementation of appropriate management actions Presents new technologies driving the next generation of sensors, allowing readers to understand new capabilities for monitoring and opportunities for another generation of sensors Includes a global vision for ocean monitoring that fosters a new perspective on the direction of ocean measurements
Acoustic Sensing Techniques For The Shallow Water Environment
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Author : Andrea Caiti
language : en
Publisher: Springer Science & Business Media
Release Date : 2006-09-21
Acoustic Sensing Techniques For The Shallow Water Environment written by Andrea Caiti and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2006-09-21 with Science categories.
This volume contains the collection of papers from the second workshop on Experimental Acoustic Inversion Techniques for Exploration of the Shallow Water Environment. Acoustic techniques provide the most effective means for remote sensing of ocean and sea floor processes, and for probing the structure beneath the sea floor. No other energy propagates as efficiently in the ocean: radio waves and visible light are severely limited in range because the ocean is a highly conductive medium. However, sound from breaking waves and coastal shipping can be heard throughout the ocean, and marine mammals communicate acoustically over basin scale distances. The papers in this book indicate a high level of research interest that has generated significant progress in development and application of experimental acoustic inversion techniques. The applications span a broad scope in geosciences, from geophysical, biological and even geochemical research. The list includes: estimation of geotechnical properties of sea bed materials; navigation and mapping of the sea floor; fisheries, aquaculture and sea bed habitat assessment; monitoring of marine mammals; sediment transport; and investigation of natural geohazards in marine sediments. Audience This book is primarily intended for physicists and engineers working in underwater acoustics and oceanic engineering. It will also be of interest to marine biologists, geophysicists and oceanographers as potential users of the methodologies and techniques described in the book contributions.
Optimal Localization Of Ocean Acoustic Sources In An Uncertain Environment
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Author : Anthony M. Richardson
language : en
Publisher:
Release Date : 1990
Optimal Localization Of Ocean Acoustic Sources In An Uncertain Environment written by Anthony M. Richardson and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1990 with Sound categories.
Model Based Ocean Acoustic Passive Localization
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Author :
language : en
Publisher:
Release Date : 1994
Model Based Ocean Acoustic Passive Localization written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1994 with categories.
The detection, localization and classification of acoustic sources (targets) in a hostile ocean environment is a difficult problem -- especially in light of the improved design of modern submarines and the continual improvement in quieting technology. Further the advent of more and more diesel-powered vessels makes the detection problem even more formidable than ever before. It has recently been recognized that the incorporation of a mathematical model that accurately represents the phenomenology under investigation can vastly improve the performance of any processor, assuming, of course, that the model is accurate. Therefore, it is necessary to incorporate more knowledge about the ocean environment into detection and localization algorithms in order to enhance the overall signal-to-noise ratios and improve performance. An alternative methodology to matched-field/matched-mode processing is the so-called model-based processor which is based on a state-space representation of the normal-mode propagation model. If state-space solutions can be accomplished, then many of the current ocean acoustic processing problems can be analyzed and solved using this framework to analyze performance results based on firm statistical and system theoretic grounds. The model-based approach, is (simply) ``incorporating mathematical models of both physical phenomenology and the measurement processes including noise into the processor to extract the desired information.`` In this application, we seek techniques to incorporate the: (1) ocean acoustic propagation model; (2) sensor array measurement model; and (3) noise models (ambient, shipping, surface and measurement) into a processor to solve the associated localization/detection problems.
Experimental Acoustic Inversion Methods For Exploration Of The Shallow Water Environment
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Author : Andrea Caiti
language : en
Publisher: Springer
Release Date : 2011-09-30
Experimental Acoustic Inversion Methods For Exploration Of The Shallow Water Environment written by Andrea Caiti and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011-09-30 with Science categories.
In recent years, research on acoustic remote sensing of the ocean has evolved considerably, especially in studying complex physical and biological processes in shallow water environments. To review the state of the art, an international workshop was held at Carvoeiro, Portugal, in March 1999, bringing together leading international researchers in the field. In contrast to much of the recent theoretical work, emphasis was placed on the experimental validation of the techniques. This volume, based on presentations at this workshop, summarizes a range of diverse and innovative applications. The invited contributions explore the use of acoustics to measure bottom properties and morphology, as well as to probe buried objects within the sediment. Within the water column, sound is applied to imaging of oceanographic features such as currents and tides or monitoring of marine life. Another key theme is the use of sound to solve geometric inverse problems for precise tracking of undersea vehicles. Audience: This volume should be useful both to the novice seeking an introduction to the field and to advanced researchers interested in the latest developments in acoustic sensing of the ocean environment. The workshop was sponsored by the Fundação para a Ciêcia e a Tecnologia (Portuguese Foundation for Science and Technology).