Download or read book Sea State Observations with an Underwater Acoustic Signal written by Leonidas Octave Jacotin and published by . This book was released on 1965 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ocean observation based on underwater acoustic technology written by Xuebo Zhang and published by Frontiers Media SA. This book was released on 2023-07-04 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Underwater Observation Using Sonar written by David Gordon Tucker and published by . This book was released on 1966 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ambient Noise in the Sea written by Robert J. Urick and published by . This book was released on 1984 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Noisy Oceans written by Gaye Bayrakci and published by John Wiley & Sons. This book was released on 2023-12-19 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Signal Processing of Underwater Acoustic Waves written by C. W. Horton and published by . This book was released on 1969 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Acoustic Observations of a Near surface Layer of Scatterers in the Sea written by Robert J. Urick and published by . This book was released on 1956 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances inUnderwater Acoustics written by Andrzej Zak and published by BoD – Books on Demand. This book was released on 2017-11-22 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Underwater acoustics, despite the relatively short history, has already found practical application in many areas of human activity. It allows, among others, depth research, data transmission, and underwater observation and provides maritime transport safety and security against terrorists. Moreover, underwater acoustic technologies are also widely used in medicine, biology, and many other fields. Therefore, it is one of the most developing areas. This book is a collection of experiences of scientists from around the world engaged in research, design, and construction, as well as the daily use of underwater acoustic systems. Giving this book in the hands of the reader, we hope that it will be a treasure trove of knowledge and inspiration for further research in the field of underwater acoustics.
Download or read book Observations of underwater sound at frequencies below 1500 Hz from breaking waves at sea written by R. D. Hollett and published by . This book was released on 1992 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Predicting the Effects of Random Ocean Dynamic Processes on Underwater Acoustic Sensing and Communication written by Byung Gu Cho and published by . This book was released on 2020 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustics is the primary means of sensing and communication in the ocean for humans and many marine animals. Natural fluctuations in the ocean, however, degrade these abilities in ways that have been previously difficult to forecast. In this thesis, we address this issue by predicting sensing and communication degradation in terms of acoustic attenuation, dispersion and temporal decorrelation at typical operational ranges and frequencies in continental-shelf environments. This is done with analytic expressions derived from first physical principles. The analytic expressions provide the statistics of the acoustic field after forward propagating through an ocean waveguide containing 3-D random inhomogeneities from the independent or combined effects of rough sea-surfaces, near-sea-surface air bubbles and internal waves. The formulation also includes Doppler effects caused by the inhomogeneities' random horizontal motion, enabling modeling and prediction over a wide range of environments and frequencies. Theoretical predictions are confirmed with available acoustic measurements in several continental-shelf environments using standard oceanographic measurements for environmental support. We quantify how the acoustic signals decorrelate over timescales determined by the underlying temporal coherence of ocean dynamic processes. Surface gravity waves and near-sea-surface air bubbles decorrelate acoustic signals over seconds or less, whereas internal waves affect acoustic coherence at timescales of several to tens of minutes. Doppler spread caused by the inhomogeneities' motion further reduces acoustic temporal coherence, and becomes important at the high frequencies necessary for communication and fine-scale sensing. We also show that surface gravity waves and bubbles in high sea states can cause increasingly significant attenuation as frequency increases. The typical durations of marine mammal vocalizations that carry over great distances are found to be consistent with the coherence timescales quantified here and so avoid random distortion of signal information even by incoherent reception.
Download or read book Observations of Ocean Fluctuations Between 15 and 23 Hour Periods in the Pacific written by Wayne Richard Blanding and published by . This book was released on 1990 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulse-like acoustic signals are transmitted from an acoustic source near Oahu to seven receivers off the west coast of the United States for a 124-day period in 1988. Acoustic travel-time oscillations are observed in the received signal at periods between 15 and 23 hours, which are caused by barotropic (or first or second mode baroclinic) flu ctuations in the ocean. It is shown that these fluctuations cannot be local processes isolated to either the source or to the receivers. It is further shown that resonant barotropic gravity wave modes (Platzman et al., 1981) are not consistent with the data. The cause of these flu ctuations remains unresolved, but the data and other oceanographic measurements put many constraints on the process causing these fluctuations.
Download or read book Applied Underwater Acoustics written by Thomas Neighbors and published by Elsevier. This book was released on 2017-01-19 with total page 982 pages. Available in PDF, EPUB and Kindle. Book excerpt: Applied Underwater Acoustics meets the needs of scientists and engineers working in underwater acoustics and graduate students solving problems in, and preparing theses on, topics in underwater acoustics. The book is structured to provide the basis for rapidly assimilating the essential underwater acoustic knowledge base for practical application to daily research and analysis. Each chapter of the book is self-supporting and focuses on a single topic and its relation to underwater acoustics. The chapters start with a brief description of the topic’s physical background, necessary definitions, and a short description of the applications, along with a roadmap to the chapter. The subtopics covered within individual subchapters include most frequently used equations that describe the topic. Equations are not derived, rather, assumptions behind equations and limitations on the applications of each equation are emphasized. Figures, tables, and illustrations related to the sub-topic are presented in an easy-to-use manner, and examples on the use of the equations, including appropriate figures and tables are also included. Provides a complete and up-to-date treatment of all major subjects of underwater acoustics Presents chapters written by recognized experts in their individual field Covers the fundamental knowledge scientists and engineers need to solve problems in underwater acoustics Illuminates, in shorter sub-chapters, the modern applications of underwater acoustics that are described in worked examples Demands no prior knowledge of underwater acoustics, and the physical principles and mathematics are designed to be readily understood by scientists, engineers, and graduate students of underwater acoustics Includes a comprehensive list of literature references for each chapter
Download or read book Analysis of Coupled Oceanographic and Acoustic Soliton Simulations in the Yellow Sea A Search for Soliton Induced Resonances written by and published by . This book was released on 2003 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The area south of the Shandong peninsula has been of great interest to both oceanographers and underwater acousticians due to the measurements of Zhou et al. [J. Acoust. Soc. Am. 90 (1991) 2042]. Over a period of years, in the summer, they observed anomalous losses in shallow water acoustic signals. They attributed the losses to acoustic mode conversions produced by solitary internal waves (solitons). Their hypothesis remains unsubstantiated due to a scarcity of oceanographic measurements in this area. In this simulation study the non-hydrostatic, 2.5-dimensional Lamb model was used to generate solitons in an adjacent, deeper area than that examined by Zhou et al. [J. Acoust. Soc. Am. 90 (1991) 2042]. Topographic variations and semi-diurnal tidal strength magnitudes were obtained from digital atlases and published data. For summer conditions, the Lamb model simulations showed that the existing semi-diurnal tidal flow over the topographic variations could lead to the formulation of internal bores and solitons. SAR observations of solitons near this region were used to select parameters and initialize the Lamb model. The resulting soliton simulations were comparable to the two-dimensional surface spectra seen in the SAR data. Soliton amplitudes of 2-7m were indicated. Acoustic studies were made using the highly accurate finite element parabolic equation (FEPE) acoustic model applied to the initial soliton state data generated by the Lamb model. Mode decomposition of the acoustic fields in the deeper region showed that the mode conversions necessary for anomalous signal losses were present. These findings are consistent with the soliton hypothesis made by Zhou et al.
Download or read book Bottom Interacting Ocean Acoustics written by William A. Kuperman and published by Springer Science & Business Media. This book was released on 2013-03-13 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt: vi These categories seem to represent the basic breakdown by field of present-day research in this area. Though each paper has been classified into one of these categories (for conference organization purpose), many papers overlapped two or three areas. It is also interesting to note that not only are scientific results being communicated, but the latest techniques and the state-of-the-art tools of the trade (existing and in development) are also being presented. The forty-six papers presented at this conference represent the work of seventy scientists working at universities, government laboratories, and industrial laboratories in seven different countries . We would like to thank the contributors for their efforts and especially for their promptness in providing the editors with their final manuscripts. William A. Kuperman Finn B. Jensen La Spezia, Italy July 1980 CONTENTS GEOACOUSTIC PROPERTIES OF MARINE SEDIMENTS Attenuation of Sound in Marine Sediments . • 1 J. M. Hovem Directivity and Radiation Impedance of a Transducer 15 Embedded in a Lossy Medium . •• •••••• G. H. Ziehm Elastic Properties Related to Depth of Burial, Strontium Content and Age, and Diagenetic Stage in Pelagic Carbonate Sediments . . • • . • • • . 41 M. H. Manghnani, S. O. Schianger, and P. D. Milholland Application of Geophysical Methods 'and Equipment to Explore the Sea Bottom . •• •••. • 53 H. F. Weichart The Acoustic Response of Some Gas-Charged Sediments in the Northern Adriatic Sea • • • • . • • • • 73 A.
Download or read book Ocean Noise and Marine Mammals written by National Research Council and published by National Academies Press. This book was released on 2003-05-22 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Ideal Program in Underwater Sound written by and published by . This book was released on 1958 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Meeting United States Japan Marine Facilities Panel written by United States-Japan Cooperative Program in Natural Resources. Panel on Marine Facilities. Meeting and published by . This book was released on with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
