Ray and Wave Chaos in Ocean Acoustics

Ray and Wave Chaos in Ocean Acoustics PDF Author: Denis Makarov
Publisher: World Scientific
ISBN: 981427318X
Category : Science
Languages : en
Pages : 412

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Book Description
1. Ray and wave propagation. 1.1. Underwater sound channel. 1.2. Basic equations. 1.3. Geometrical optics approximations and optical-mechanical analogy. The Hamiltonian formalism. 1.4. Ray travel times. 1.5. Range-dependent environments. 1.6. Acoustic ocean tomography. 1.7. Experiments on long-range sound propagation. 1.8. Summary -- 2. Ray chaos. 2.1. Hamiltonian chaos. 2.2. Lyapunov instability. 2.3. Ray-medium resonance. 2.4. Overlapping of resonances. 2.5. Vertical resonance. 2.6. Manifestation of regular and chaotic ray motion in distributions of ray travel times. 2.7. Summary -- 3. Wave chaos. 3.1. The problem of wave chaos. 3.2. Normal modes. 3.3. Mode coupling under chaotic conditions. 3.4. Influence of fine-scale inhomogeneities on wave dynamics. 3.5. Summary -- 4. Chaotic phenomena in random environment. 4.1. Ray chaos in a random medium. 4.2. Travel times of chaotic rays. 4.3. Modal structure of the sound field in a waveguide with random inhomogeneities. 4.4. Wave beam in an ocean acoustic waveguide. 4.5. Arrival times of sound pulses in the presence of internal waves and a mesoscale inhomogeneity. 4.6. Summary -- 5. Glossary of some concepts and notations in Hamiltonian chaos theory

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.

Ray And Wave Chaos In Ocean Acoustics: Chaos In Waveguides

Ray And Wave Chaos In Ocean Acoustics: Chaos In Waveguides PDF Author: Denis Makarov
Publisher: World Scientific
ISBN: 9814467979
Category : Science
Languages : en
Pages : 412

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Book Description
A systematic study of chaotic ray dynamics in underwater acoustic waveguides began in the mid-1990s when it was realized that this factor plays a crucial role in long-range sound propagation in the ocean. The phenomenon of ray chaos and its manifestation at a finite wavelength — wave chaos — have been investigated by combining methods from the theory of wave propagation and the theory of dynamical and quantum chaos.This book is the first monograph summarizing results obtained in this field. Emphasis is made on the exploration of ray and modal structures of the wave field in an idealized environmental model with periodic range dependence and in a more realistic model with sound speed fluctuations induced by random internal waves. The book is intended for acousticians investigating the long-range sound transmission through the fluctuating ocean and also for researchers studying waveguide propagation in other media. It will be of major interest to scientists working in the field of dynamical and quantum chaos.

Ray and Wave Chaos in Ocean Acoustics

Ray and Wave Chaos in Ocean Acoustics PDF Author: Denis Makarov
Publisher: World Scientific
ISBN: 9814273171
Category : Science
Languages : en
Pages : 412

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Book Description
A systematic study of chaotic ray dynamics in underwater acoustic waveguides began in the mid-1990s when it was realized that this factor plays a crucial role in long-range sound propagation in the ocean. The phenomenon of ray chaos and its manifestation at a finite wavelength ? wave chaos ? have been investigated by combining methods from the theory of wave propagation and the theory of dynamical and quantum chaos. This book is the first monograph summarizing results obtained in this field. Emphasis is made on the exploration of ray and modal structures of the wave field in an idealized environmental model with periodic range dependence and in a more realistic model with sound speed fluctuations induced by random internal waves. The book is intended for acousticians investigating the long-range sound transmission through the fluctuating ocean and also for researchers studying waveguide propagation in other media. It will be of major interest to scientists working in the field of dynamical and quantum chaos.

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.

Understanding Ocean Acoustics

Understanding Ocean Acoustics PDF Author: Jens M. Hovem
Publisher: Cambridge Scholars Publishing
ISBN: 1527529258
Category : Science
Languages : en
Pages : 211

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Book Description
Underwater acoustics is important in all underwater sonar systems for object detection, classification, surveillance and for communications links for military and civilian purposes. Sound is also a major tool for studying the ocean environment and the interaction of sound and marine life in general. Understanding Ocean Acoustics emphasises such applications and issues relevant to studies of the ocean environment and aquatic life. Its focus is therefore environmental research and development using low frequencies relevant to fish and sea mammals. For such frequencies, the geoacoustic properties of the bottom cannot be ignored, which requires knowledge about waves in solids, which is missing in most books on underwater acoustics.

Investigating Chaos in Ocean Acoustics

Investigating Chaos in Ocean Acoustics PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 91

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Book Description
Chaos is a term assigned to a class of motions in deterministic systems whose time history has a sensitive dependence on initial conditions. Such phenomenon has previously been shown to exhibit in ocean acoustics ray tracing, and called ray chaos by the ocean acoustics community. Since 1995, we have made a further investigation on the ray chaos, as a basic research sponsored by the Office of Naval Research (Grant No. N00014-95-10443). The results of this investigation are presented in this report. Two new topics are addressed. The first is the chaos in three-dimensional (3-D) ray tracing. We study the chaos in Heard-to-Ascension (HA) propagation, and California-to-Hawaii (CH) propagation. Chaos appeared in both cases. Loss of predictability occurred in HA case. However, CH problem was predicted with high accuracy even in the presence of chaos. Comparison between the HA and the CH case leads to a hypothesis on overcoming ray chaos. The signature of chaos in the received signals is discussed. The second topic is the chaos in double-channel propagation. We use the 2-D equations and a double-channel model to study the effects of internal waves on chaos. Then we use the 3-D ray equations and measured sound speed data to conduct a further investigation. Numerical results show that chaos in a double-channel is likely to be induced by internal waves. Much larger chaoticity was observed when measured sound speed data were used.

Ocean Acoustics

Ocean Acoustics PDF Author: J.A. DeSanto
Publisher: Springer Science & Business Media
ISBN: 3642812945
Category : Science
Languages : en
Pages : 295

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Book Description
This Topics volume is devoted to a study of sound propagation in the ocean. The effect of the interior of the ocean on underwater sound is analogous to the effect of a lens on light. The oceanic lens is related, as in light propagation, to the index of refraction of the medium. The latter is giv~n by the ratio of the sound frequency to the speed of sound in water, typi ca lly about 1500 m s -1. It is the vari ation of the sound speed due to changing temperature, density, salinity, and pres sure in the complex ocean environment which creates the lens effect. Many oceanic processes such as currents, tides, eddies (circulating, translating regions of wa ter), and internal waves (the wave-like structure of the oceanic density variabil ity) contri bute in turn to the changes in sound speed'. The net effect of the ocean lens is to trap and guide sound waves in a channel created by the lens. The trapped sound can then propagate thousands of miles in this oceanic waveguide. In addition to the propagation in the interior of the ocean, sound can propagate into and back out of the ocean bottom as well as scatter from the ocean surface. Just as the sound produced by a loudspeaker in a room is affected by the walls of the room, so the ocean boundaries and the material properties below the ocean bottom are essential ingredients in the problem.

Fundamentals of Ocean Acoustics

Fundamentals of Ocean Acoustics PDF Author: Leonid M. Brekhovskikh
Publisher: Springer Science & Business Media
ISBN: 3662073285
Category : Science
Languages : en
Pages : 281

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Book Description
As man turns his attention from the overcrowded continents of this planet and explores the spaciousness of the ocean, the applications of ocean acoustics become increasingly numerous and important. This book pro- vides an up-to-date introduction to the theory of sound propagation in the ocean, with much new material having been added throughout the second edition. It includes both ray and wave treatments and considerable attention is paid to stochastic problems such as the scattering of sound at rough surfaces and random inhomogeneties. An introductory chapter that discusses the basic experimental data complements the following theoretical chapters.

Ocean and Seabed Acoustics

Ocean and Seabed Acoustics PDF Author: George V. Frisk
Publisher: Pearson Education
ISBN: 0132441543
Category : Technology & Engineering
Languages : en
Pages : 391

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Book Description
Respected scientist and educator George V. Frisk draws on his extensive professional experience to demonstrate how the ocean environment provides an excellent setting in which to display general principles of wave propagation that are also applicable to other areas of wave physics. Ocean and Seabed Acoustics proceeds with a derivation of elementary solutions to the wave equation in free space and then progressively addresses problems of increasing complexity. This book concludes with a discussion of acoustic wave propagation due to a point source in an inhomogeneous waveguide with lossy boundaries.

Sound Propagation in the Sea

Sound Propagation in the Sea PDF Author: Robert J. Urick
Publisher:
ISBN:
Category : Sound
Languages : en
Pages : 268

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Book Description