Download or read book Environment Variability in the Deep Sound Channel written by Eric J. Softley and published by . This book was released on 1977 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deep ocean moored thermistor string buoys were constructed to obtain vertical temperature profiles at depths down to 1500 meters. A requirement for data acquisition in near real time was met by means of on-board signal conditioning and prompt radio transmission to a computer equipped shore station for automatic processing and subsequent use in relating acoustic propagation to temporal variations along designated acoustic paths. Two such buoy systems were launched. One was successfully implanted in about 4800 meters of water providing some 1000 hours of real time on-station temperature, environmental and housekeeping data while the second was lost during the final stage of deployment. A complete description of the equipment along with design considerations and techniques utilized is appended. (Author).
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 Draft Environmental Impact Statement for the Kauai Acoustic Thermometry of Ocean Climate Project and Its Associated Marine Mammal Research Program written by Clayton H Spikes and published by . This book was released on 1994 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kauai Acoustic Thermometry of Ocean Climate ATOC Project and Marine Mammal Research Program MMRP written by and published by . This book was released on 1995 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Variability in the Lincoln Sea During the ICESHELF 1988 1991 Exercises written by Paul J. Bucca and published by . This book was released on 1992 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ocean Variability Acoustic Propagation written by J. Potter and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 599 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Marine Research written by and published by . This book was released on 1973 with total page 1200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book North Pacific Acoustic Laboratory written by and published by . This book was released on 2001 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book California Acoustic Thermometry of Ocean Climate ATOC Program and Marine Mammal Research MMRP Program Monterey County written by and published by . This book was released on 1995 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book EDS Environmental Data Service written by United States. Environmental Data Service and published by . This book was released on 1978 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book EDIS Environmental Data and Information Service written by United States. Environmental Data and Information Service and published by . This book was released on 1978 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Systems Volume I written by Achim Sydow and published by EOLSS Publications. This book was released on 2010-09-27 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental Systems is a component of Encyclopedia of Environmental and Ecological Sciences, Engineering and Technology Resources in the global Encyclopedia of Life Support Systems (EOLSS), which is an integrated compendium of twenty one Encyclopedias. Environmental Systems is something about data handling, modeling and decision making in the field of environmental systems. It includes related basic knowledge on measurement techniques, modeling techniques and models and their applications for decisions making. Environmental engineering / research are based on measurement techniques and related knowledge of natural and life sciences. Developed mathematical and numerical simulation models are tools and strictly purpose oriented, that means suitable for decision making. The three volumes on Environmental Systems are aimed at the following five major target audiences: University and College students Educators, Professional practitioners, Research personnel and Policy analysts, managers, and decision makers and NGOs.
Download or read book Underwater Sound Propagation and Acoustic Communication in a Time varying Shallow Estuarine Environment written by Zheguang Zou and published by . This book was released on 2018 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Estuaries are water regions that connect rivers and oceans, which are very important due to heavy traffic, fishery and other coastal engineering activities. Underwater acoustic technology offers a series of effective applications and technical supports for real-time monitoring and long-term preservation of the nature environment and ecosystem in these regions. However, estuaries are shallow waters with complicated temporal and spatial environmental variability, involving a variety of physical oceanographic processes, such as tidal water mixing and ocean winds/waves, which can significantly influence the underwater sound propagation and moreover, underwater acoustic communications. In order to perform reliably and effectively in such complex time-varying shallow-water ocean environments, next-generation underwater acoustic communication systems need an all new design based on the environmental variability of the physical ocean, which takes the environmental physics and time-varying variability into account and is able to adapt and switch to the optimal mode as the environment evolves. Therefore, a deep, comprehensive and thorough understanding of the link between the time-varying ocean environment, underwater acoustic channel, and underwater acoustic communication systems is highly required. ☐ This dissertation investigated the relationship between the shallow-water, time-varying environment of estuaries, the underwater sound propagation and underwater acoustic communications, which can help the design of underwater acoustic systems so that they can adapt the time-varying environment with wiser parameter configurations. In this dissertation, field data analysis, joint numerical modeling, together with a controllable laboratory experiment were used to study acoustic channel variability of a shallow estuary and its influence on the performance of underwater acoustic communications. This dissertation included four aspects: (a) Effect of water-column variation due to the tidal dynamics in an estuary on the underwater acoustic direct path; (b) Effect of time-varying surface roughness due to the wind-driven waves on underwater acoustic surface paths; (c) Numerically modeling the effect of time-varying wind-driven shallow-water waves on coherent underwater acoustic communications using a combined model; (d) Conducting a controllable laboratory experiment to investigate the time-varying wind-driven water waves on the performance of coherent and non-coherent underwater acoustic communications. ☐ The first two aspects focused on the link between the time-varying environment of an estuary and the underwater acoustic wave propagation. With field data analysis and joint numerical modeling, the time-varying variability of acoustic direct paths and surface-bounced paths from a high-frequency acoustic experiment conducted in the Delaware Bay estuary was explored. On one hand, periodical acoustic direct path fading was found in the tidal-straining Delaware Bay estuary, with the fading period as same as the semi-diurnal tide. Based on physical oceanography and ocean acoustics, the mechanism that causes the direct path fading and its link to the water dynamics of an estuary was investigated. On the other hand, the relationship between the acoustic surface paths and the surface wind speed was investigated, and the wind-influenced shallow-water time-varying channel was studied using field data analysis and a joint model combining physical oceanography and ocean acoustics. The joint numerical model, including a wind-wave model, a surface generation algorithm and a parabolic equation acoustic model, reproduced the relationship between the wind speed and surface reflection signals. ☐ The last two aspects applied the knowledge of underwater sound propagation in shallow estuaries into analyzing the performance of underwater acoustic communication systems, i.e., investigating how the fast fluctuation of a shallow-water environment (wind-driven waves) influences different fundamental modulation schemes for underwater acoustic communications. To better analyze the effect of environmental variability of the physical ocean on underwater acoustic communications, the surface condition was set as the only variation in the numerical modeling and the controllable laboratory experiment. On one hand, a combined model including physical oceanography, ocean acoustics, and underwater acoustic communication was used to study the time-varying underwater acoustic channel under different wind speeds, and the performance of the coherent acoustic communication (QPSK) system. On the other hand, a controllable laboratory experiment was conducted to investigate bit-error-rate (BER) performance of the MFSK (representing the non-coherent acoustic communication) and the QPSK (representing the coherent acoustic communication) acoustic modulations. ☐ The main conclusions of the dissertation are as follows. For the time-varying variability of underwater acoustic channel: (a) Due to the tidal-straining water dynamics of an estuary, periodical water column exchange between the seawater and the freshwater, up-refracting sound speed profile is more likely to form by the end of ebb tide, which redirects sound signal away from the deep receivers and creates shadow zone for the sound direct path; (b) In an open estuary, the acoustic pressure of surface-bounced paths decreases with increased wind speed, as a result of increased acoustic scattering due to the wind-driven surface roughness. For underwater acoustic communications: (c) Coherent acoustic communications are sensitive to the fast time-varying variability, and performance decrease significantly with increased wind speed, as a result of increased channel variability and decreased temporal coherence; (d) Non-coherent acoustic communications are less sensitive to the channel variability, and the reduced multipath signals due to wind-wave surface may improve the system performance. ☐ The key novelties of this dissertation include: (a) Using a joint model involving physical oceanography and ocean acoustics to study the effect of time-varying estuarine environment (water-column variations and wind-driven surface waves) on underwater sound propagation and the underwater acoustic channels. (b) Using an integrated model involving physical oceanography, ocean acoustics, and underwater acoustic communications to study the effect of time-varying estuarine environment (wind-driven surface waves) on underwater acoustic communications. (c) Using field experimental data, numerical modeling and controllable laboratory experiment to study the underwater sound propagation and underwater acoustic communications in a time-varying ocean environment.
Download or read book Naval Research Reviews written by and published by . This book was released on 1983 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Springer Handbook of Acoustics written by Thomas Rossing and published by Springer. This book was released on 2015-01-15 with total page 1280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience and others. Here is an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents spanning: animal acoustics including infrasound and ultrasound, environmental noise control, music and human speech and singing, physiological and psychological acoustics, architectural acoustics, physical and engineering acoustics, medical acoustics and ocean acoustics. The Springer Handbook of Acoustics reviews the most important areas of acoustics, 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, e.g. computer recognition and synthesis of speech, physiological acoustics, psychological acoustics, thermoacoustics, diagnostic imaging and therapeutic applications and acoustical oceanography. This new edition of the Handbook features over 11 revised and expanded chapters, new illustrations and two new chapters covering microphone arrays, acoustic metamaterials and acoustic emission. These improvements will make the handbook even more useful as a reference and a guide for researchers and students in every branch of acoustics. Praise for the first edition: "This treatise is a successful attempt to cover in one book the diverse field of acoustics, which ranges from physics to music and from formal mathematics to technological applications. ... It is this reviewer's opinion that a handbook like Rossing's, which covers the whole field of acoustics, serves a real purpose because it not only gives one a chance to see how one's specialty is covered but it also permits one to make a quick survey of other acoustical areas." (Leo Beranek, American Journal of Physics, Vol. 77 (12), December, 2009) "The Springer Handbook of Acoustics falls into that exceptional list. ...every physics department should have a copy available." (John L. Hubisz, The Physics Teacher, Vol. 48, March, 2010) "This handbook is an excellent addition to the acoustics literature. ... The handbook nicely covers both basics and advances in several areas of acoustics. Several chapters provide good mathematical depth, making the handbook useful as a research and technical resource. ...Overall, a very useful educational and research resource. Summing Up: Recommended. Upper-division undergraduates through professionals." (M. G. Prasad, CHOICE, Vol. 45 (5), January, 2008) "This book covers a wide range of topics and the inclusion of musical acoustics, computer and electronic music appeal to me (singer, song-writer, performer and recording studio co-owner). This handbook is probably well suited for an undergraduate-level introduction to an acoustics course. ... The wide range of topics, inclusion of music-related chapters, eye-pleasing presentations and other useful features make this a very good book to have on your shelf." (Tim Casey, International Journal of Acoustics and Vibration, Vol. 13 (1), 2008) "The Springer Handbook of Acoustics comprises 28 chapters written by 33 authors. The Handbook of Acoustics is useful as a source book for anyone who needs or wants to become familiar with the jargon and issues related to a specific subfield of acoustics ... ." (Robert I. Odom, Siam Review, Vol. 50 (3), 2008) The Springer Handbook of Acoustics reviews the most important areas of acoustics, 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, e.g. computer recognition and synthesis of speech, physiological acoustics, psychological acoustics, thermoacoustics, diagnostic imaging and therapeutic applications and acoustical oceanography. This new edition of the Handbook features over 13 revised and expanded chapters, new illustrations and 3 new chapters covering microphone arrays, acoustic metamaterials and acoustic emission. These improvements will make the handbook even more useful as a reference and a guide for researchers and students in every branch of acoustics.
Download or read book Impact of Littoral Environmental Variability on Acoustic Predictions and Sonar Performance written by Nicholas G. Pace and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Surveillance Towed Array Sensor System Low Frequency Active SURTASS LFA Sonar written by and published by . This book was released on 2001 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
