Acoustical Properties of the Sea Floor Relevant to Long-Range Sonar Performance in the Oceans

Acoustical Properties of the Sea Floor Relevant to Long-Range Sonar Performance in the Oceans

Author: George M. Bryan

Publisher:

Published: 1972

Total Pages: 15

ISBN-13:

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The overall objective of this research is an understanding of the relationship between the physical structure of the sea floor and its acoustic response, so that knowledge of one can be used to make inferences about the other. Inferences in both directions are important: the use of acoustics to investigate the physical and geophysical nature of the ocean floors is well known. Equally important is the ability to predict the acoustic response of the sea floor on the basis of its measurable physical properties.


Final Report. NAVSHIPS Contract N00024-69-C-1184

Final Report. NAVSHIPS Contract N00024-69-C-1184

Author: George M. Bryan

Publisher:

Published: 1970

Total Pages: 17

ISBN-13:

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The research was part of a continuing program in which the Observatory has investigated acoustical properties of the sea floor relevant to long-range sonar performance in the oceans. The principal objective is the prediction of acoustic bottom loss at sonar frequencies as a function of geographical position. The bottom-reflected acoustic path is of paramount importance in present-day long range sonar systems and bottom loss is the crucial factor in determining the usefulness of this path. Thus it is essential to predict levels of bottom loss in areas where long-range sonar is to be used. (Author).


Acoustic and Related Properties of the Sea Floor

Acoustic and Related Properties of the Sea Floor

Author: Edwin Lee Hamilton

Publisher:

Published: 1975

Total Pages: 28

ISBN-13:

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The general objectives of this investigation were to determine and study those characteristics of the sea floor that affect sound propagation and the prediction of sonar performance; to support underwater acoustics' experiments and theory by furnishing information on the mass physical properties of sediments and rocks in the form of geoacoustic models of the sea floor; and to develop models of the sea floor which include gradients of sound velocity and attenuation, density, and elastic properties. Specifically, the minor objectives were to revise and review earlier work on the relations between frequency and attenuation of compressional (sound) waves in marine sediments and on the relations between attenuation and sediment porosity. The major objectives were to determine and predict variations of the attenuation of sound waves with depth in the sea floor.


High-Frequency Seafloor Acoustics

High-Frequency Seafloor Acoustics

Author: Darrell Jackson

Publisher: Springer Science & Business Media

Published: 2007-08-02

Total Pages: 634

ISBN-13: 0387369457

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This book is a research monograph on high-Frequency Seafloor Acoustics. It is the first book in a new series sponsored by the Office of Naval Research on the latest research in underwater acoustics. It provides a critical evaluation of the data and models pertaining to high-frequency acoustic interaction with the seafloor, which will be of interest to researchers in underwater acoustics and to developers of sonars. Models and data are presented so as to be readily usable, backed up by extensive explanation. Much of the data is new, and the discussion in on two levels: concise descriptions in the main text backed up by extensive technical appendices.


Final Report 15 November 1966-28 February 1969 on Navships Contract N00024-67-c-1186

Final Report 15 November 1966-28 February 1969 on Navships Contract N00024-67-c-1186

Author: George M. Bryan

Publisher:

Published: 1970

Total Pages: 15

ISBN-13:

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The research was directed primarily at the investigation of acoustical properties of the sea floor relevant to long range sonar performance in the oceans. In many situations involving long range sonar it is necessary to depend on the bottom-reflected path. It is therefore essential to be able to predict the bottom loss which may be encountered in areas where long-range sonar is to be used. (Author).


Final Report, 1 October 1960-30 September 1966

Final Report, 1 October 1960-30 September 1966

Author: George M. Bryan

Publisher:

Published: 1969

Total Pages: 15

ISBN-13:

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The principal aim of the research was the investigation of acoustical properties of the sea floor relevant to long-range sonar performance in the oceans of the world. In many situations involving long-range sonar it is necessary to depend on the bottom-reflected path. The topographic relief of the water sediment interface itself, based on precision echo sounding; and the material properties of the first few meters of sediment, by means of deep-sea coring. (Author).


Ocean Noise and Marine Mammals

Ocean Noise and Marine Mammals

Author: National Research Council

Publisher: National Academies Press

Published: 2003-05-22

Total Pages: 220

ISBN-13: 0309133157

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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.


Impact of Littoral Environmental Variability on Acoustic Predictions and Sonar Performance

Impact of Littoral Environmental Variability on Acoustic Predictions and Sonar Performance

Author: Nicholas G. Pace

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 592

ISBN-13: 9401006261

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The limiting influence of the environment on sonar has long been recognised as a major challenge to science and technology. As the area of interest shifts towards the lit toral, environmental influences become dominant both in time and space. The manyfold challenges encompass prediction, measurement, assessment and adaptive responses to maximize the effectiveness of systems. Although MCM and ASW activities are dom inated in different ways and scales by the environment, both warfare areas have had to consider the significantly changing requirements posed by operations in the littoraL The fundamental scientific issues involved in developing models relating acoustics to the environment are matched in difficulty by the need for data for their validation and eventual practical use for prediction. In many instances the need is for on-line adaptation of systems to changing circumstances whilst other needs are for the Ionger term planning activities. This book and the attached full-color CD are the proceedings of a conference organ ised by the SACLANT Undersea Research Centre, held at Villa Marigola, Lerici, Italy, on 16-20 September 2002. The fundamental problems associated with environmental 1 variability and sonar were explored at a previous SACLANTCEN conference in 1990. These problems have not gone away but, on the one hand are exaggerated by the move to the littoral and on the other hand, are open to treatrnent in new ways that advances in technology and computer power allow.


Springer Handbook of Acoustics

Springer Handbook of Acoustics

Author: Thomas Rossing

Publisher: Springer Science & Business Media

Published: 2007-06-21

Total Pages: 1179

ISBN-13: 0387304460

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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.