Sound Propagation through the Stochastic Ocean

Sound Propagation through the Stochastic Ocean PDF Author: John A. Colosi
Publisher: Cambridge University Press
ISBN: 1107072344
Category : Mathematics
Languages : en
Pages : 443

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Book Description
In this book, key discoveries in the field of statistical ocean acoustics over the last 35 years are addressed with illustrations from ocean observations.

Sound Propagation through the Stochastic Ocean

Sound Propagation through the Stochastic Ocean PDF Author: John A. Colosi
Publisher: Cambridge University Press
ISBN: 1107072344
Category : Mathematics
Languages : en
Pages : 443

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Book Description
In this book, key discoveries in the field of statistical ocean acoustics over the last 35 years are addressed with illustrations from ocean observations.

Fundamentals of Ocean Acoustics

Fundamentals of Ocean Acoustics PDF Author: L. Brekhovskikh
Publisher: Springer Science & Business Media
ISBN: 3662023423
Category : Science
Languages : en
Pages : 262

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Book Description
The continents of our planet have already been exploited to a great extent. Therefore man is turning his sight to the vast spaciousness of the ocean whose resources - mineral, biological, energetic, and others - are just beginning to be used. The ocean is being intensively studied. Our notions about the dynam ics of ocean waters and their role in forming the Earth's climate as well as about the structure of the ocean bottom have substantially changed during the last two decades. An outstanding part in this accelerated exploration of the ocean is played by ocean acoustics. Only sound waves can propagate in water over large distances. Practically all kinds of telemetry, communication, location, and re mote sensing of water masses and the ocean bottom use sound waves. Propa gating over thousands of kilometers in the ocean, they bring information on earthquakes, eruptions of volcanoes, and distant storms. Projects using acoustical tomography systems for exploration of the ocean are presently be ing developed. Each of these systems will allow us to determine the three-di mensional structure of water masses in regions as large as millions of square kilometers.

Ocean Variability & Acoustic Propagation

Ocean Variability & Acoustic Propagation PDF Author: J. Potter
Publisher: Springer Science & Business Media
ISBN: 9401133123
Category : Science
Languages : en
Pages : 599

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Book Description
Fifteen years ago NATO organised a conference entitled 'Ocean Acoustic Modelling'. Many of its participants were again present at this variability workshop. One such participant. in concluding his 1975 paper, quoted the following from a 1972 literature survey: ' ... history presents a sad lack of communications between acousticians and oceanographers' Have we done any better in the last 15 years? We believe so, but only moderately. There is still a massive underdeveloped potential for acousticians and oceanographers to make significant progress together. Currently, the two camps talk together insufficiently even to avoid simple misun derstandings. such as those in Table 1. Table 1 Ocsanographic and acoustic jargon (from an idea by Pol/ardi Jargon Oceanographic use Acoustic use dbordB decibar (depth in m) decibel (energy level) PE primitive equations parabolic equations convergence zone converging currents converging rays (downwelling water) (high energy density) front thermohaline front wave, ray or time front speed water current speed sound propagation speed 1 The list goes on.

Applied Mechanics Reviews

Applied Mechanics Reviews PDF Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 952

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Book Description


The Shock and Vibration Digest

The Shock and Vibration Digest PDF Author:
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 688

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Book Description


Space-frequency Correlations in Multistatic Acoustic Reverberation Due to a Wind-driven Sea Surface

Space-frequency Correlations in Multistatic Acoustic Reverberation Due to a Wind-driven Sea Surface PDF Author: R. F. Gragg
Publisher:
ISBN:
Category : Seawater
Languages : en
Pages : 60

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Book Description
Analytic methods are used to assess the impact of the two-dimensional (2-D) wave spectrum of a wind-driven sea on multistatic low-frequency surface reverberation. The problem is initially posed with a narrowband source beneath a time-dependent sea surface in an ocean that can have depth dependence and bottom layering. The propagated signal interacts with the slower moving surface waves to produce a narrowband scattered field. The small-waveheight approximation is applied to a deterministic sea surface to express the scattered field in terms of the surface elevation and the Green's function for a perfectly calm sea. Randomness is then incorporated into the surface description, and its impact is formulated for an arbitrarily placed pair of receivers. The three-dimensional (3-D) cross-spectral density (CSD) of the reverberation is reduced to a sum of baseband and sideband terms formulated as multiple mean-sea-surface integrals. The sideband result is identified as an active scattering generalization of the van Cittert-Zernike theorem from partial coherence theory. The focus is then narrowed to shallow deployment in a homogeneous ocean, and stationary-phase estimates are used to produce analytic expressions for the CSD. The zero-Doppler component and Bragg-Doppler sidebands are expressed in terms of the power spectrum of the source, the power spectrum and directionality of the surface waves, and the multistatic source/receiver geometry. Sample sideband calculations are provided to illustrate the results, and system implications are considered.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 702

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Book Description


Sea Surface Sound '94 - Proceedings Of The Iii International Meeting On Natural Physical Processes Related To Sea Surface Sound

Sea Surface Sound '94 - Proceedings Of The Iii International Meeting On Natural Physical Processes Related To Sea Surface Sound PDF Author: Michael J Buckingham
Publisher: World Scientific
ISBN: 981453188X
Category :
Languages : en
Pages : 512

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Book Description
Understanding and constructively using natural sound in the ocean has become of prime importance with the shift of emphasis to protecting the environment and exercising responsible global resource management which has followed the end of the Cold War. Especially now that we realise that marine mammals and other inhabitants of the oceans are threatened by our acoustic pollution of their environment, the use of natural sound as a non-intrusive remote sensing probe has become particularly germane. This was the first meeting on the subject since the fall of Soviet-Western barriers, and the proceedings include significant work from premier researchers in the former Soviet Union. It was also the first meeting which specifically addressed the new and exciting idea of using natural sound in applications for monitoring the marine environment. The proceedings include a number of papers on various aspects of this topic. Further new work on the basic physics of sound production and propagation is also included. This volume includes leading-edge work from the foremost researchers in the field, including Bill Carey, Lawrence Crum, Nikolai Dubrovskii, David Farmer, Brian Kerman, Bill Kuperman, Michael Longuet-Higgins, Hank Medwin, Ken Melville, A Prosperetti and many others.

Cavitation and Inhomogeneities in Underwater Acoustics

Cavitation and Inhomogeneities in Underwater Acoustics PDF Author: W. Lauterborn
Publisher: Springer Science & Business Media
ISBN: 3642510701
Category : Science
Languages : en
Pages : 325

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Book Description


Fundamentals of Acoustical Oceanography

Fundamentals of Acoustical Oceanography PDF Author: Herman Medwin
Publisher: Academic Press
ISBN: 0080532160
Category : Science
Languages : en
Pages : 739

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Book Description
The developments in the field of ocean acoustics over recent years make this book an important reference for specialists in acoustics, oceanography, marine biology, and related fields. Fundamentals of Acoustical Oceanography also encourages a new generation of scientists, engineers, and entrepreneurs to apply the modern methods of acoustical physics to probe the unknown sea. The book is an authoritative, modern text with examples and exercises. It contains techniques to solve the direct problems, solutions of inverse problems, and an extensive bibliography from the earliest use of sound in the sea to present references.Written by internationally recognized scientists, the book provides background to measure ocean parameters and processes, find life and objects in the sea, communicate underwater, and survey the boundaries of the sea. Fundamentals of Acoustical Oceanography explains principles of underwater sound propagation, and describes how both actively probing sonars and passively listening hydrophones can reveal what the eye cannot see over vast ranges of the turbid ocean. This book demonstrates how to use acoustical remote sensing, variations in sound transmission, in situ acoustical measurements, and computer and laboratory models to identify the physical and biological parameters and processes in the sea.* Offers an integrated, modern approach to passive and active underwater acoustics* Contains many examples of laboratory scale models of ocean-acoustic environments, as well as descriptions of experiments at sea* Covers remote sensing of marine life and the seafloor* Includes signal processing of ocean sounds, physical and biological noises at sea, and inversions* resents sound sources, receivers, and calibration* Explains high intensities; explosive waves, parametric sources, cavitation, shock waves, and streaming* Covers microbubbles from breaking waves, rainfall, dispersion, and attenuation* Describes sound propagation along ray paths and caustics* Presents sound transmissions and normal mode methods in ocean waveguides