Ocean Acoustics Program PDF Download

Author: J. Michael McKisic
Publisher:
ISBN:
Category : Underwater acoustics
Languages : en
Pages : 108

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Author: Ivan Tolstoy
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 404

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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.

Author: Carey D. Smith
Publisher:
ISBN:
Category : Underwater acoustics
Languages : en
Pages : 64

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Book Description
The role of the U.S. Navy as a credible world sea power is placing increasing demands on sonar systems development for ASW. The management of the Navy's Ocean Environmental Acoustic Program (EVA) is of great concern because of the critical nature of this support service to systems development. At present, sonar developers and operators do not have sufficient EVA data and models available for optimum systems design and use. The deficiency is primarily due to a technological gap between EVA program outputs and the system developers requirements. The most effective and efficient management and implementation of the EVA program is therefore required. A detailed plan for a program management structure in NAVSEA (Sonar Technology Division) is presented; it calls for the establishment of a technical group assigned the responsibility for developing and maintaining a working relationship between environmental acousticians and systems developers.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309133157
Category : Science
Languages : en
Pages : 220

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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.

Author: Finn B. Jensen
Publisher: Springer Science & Business Media
ISBN: 1441986782
Category : Science
Languages : en
Pages : 808

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Senior level/graduate level text/reference presenting state-of-the- art numerical techniques to solve the wave equation in heterogeneous fluid-solid media. Numerical models have become standard research tools in acoustic laboratories, and thus computational acoustics is becoming an increasingly important branch of ocean acoustic science. The first edition of this successful book, written by the recognized leaders of the field, was the first to present a comprehensive and modern introduction to computational ocean acoustics accessible to students. This revision, with 100 additional pages, completely updates the material in the first edition and includes new models based on current research. It includes problems and solutions in every chapter, making the book more useful in teaching (the first edition had a separate solutions manual). The book is intended for graduate and advanced undergraduate students of acoustics, geology and geophysics, applied mathematics, ocean engineering or as a reference in computational methods courses, as well as professionals in these fields, particularly those working in government (especially Navy) and industry labs engaged in the development or use of propagating models.

Author: T. Akal
Publisher: Springer Science & Business Media
ISBN: 1461322014
Category : Science
Languages : en
Pages : 898

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Book Description
Seafloor investigation has long been a feature of not only seismology but also of acoustics. Indeed it was acoustics that produced depth sounders, giving us the first capability of producing both global and local maps of the seafloor. Subsequently, better instrumentation and techniques led to a clearer, more quantitative picture of the seabed itself, which stimulated new hypotheses such as seafloor spreading through the availability of more reliable data on sediment thickness over ocean basins and other bottom features. Geologists and geophysicists have used both acoustic and seismic methods to study the seabed by considering the propagation of signals arising from both natural seismic events and man-made impulsive sources. Although significant advances have been made in instrumentation, such as long towed geophysical arrays, ai r guns and ocean bot tom seismometers, the pic ture of the seafloor is still far from complete. Underwater acoustics concerns itself today with the phenomena of propagation and noise at frequencies and ranges that require an understanding of acoustic interaction at both of its boundaries, the sea surface and seafloor, over depths ranging from tens to thousands of meters. Much of the earlier higher frequency (>1 kHz) work included the characterization of the seafloor in regimes of reflection coefficients which were empirically derived from surveys. The results of these studies met with only limited success, confined as they were to those areas where survey data existed and lacking a physical understanding of the processes of reflection and scattering.

Author: United States. Department of Defense
Publisher:
ISBN:
Category : Military research
Languages : en
Pages : 88

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Author: Thomas Rossing
Publisher: Springer Science & Business Media
ISBN: 0387304460
Category : Science
Languages : en
Pages : 1179

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Book Description
This is an unparalleled modern handbook reflecting the richly interdisciplinary nature of acoustics edited by an acknowledged master in the field. The handbook reviews the most important areas of the subject, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest research and applications are incorporated throughout, including computer recognition and synthesis of speech, physiological acoustics, diagnostic imaging and therapeutic applications and acoustical oceanography. An accompanying CD-ROM contains audio and video files.

Author: Oleg A. Godin
Publisher: World Scientific
ISBN: 9812568255
Category : Technology & Engineering
Languages : en
Pages : 1272

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Book Description
This book describes, using first-person accounts, the history of the development in the Soviet Union and, later, in Russia of an extremely important technical field and how that history was influenced by WWI, WWII, and the Cold War, by government bureaucracy, in both positive and negative ways, by the economic collapse of the Soviet Union, and most importantly, by the dedicated efforts of vast numbers of individuals, including some of the greatest scientific minds of the 20th century. It will make fascinating reading for engineers and scientists who were engaged in similar work in the West, for historians of the Cold War and of the Soviet Union, and for present day researchers who need to learn about Russian scientific contributions.Because of its importance to national security, much of the research and development effort in underwater acoustics was classified during the Cold War, both in the Soviet Union and the United States. This book presents the first declassified accounts of the development of numerous hydroacoustic systems by individuals having first-hand knowledge of the development efforts.