Download or read book A Review of Underwater Acoustic Systems and Methods for Locating Objects Lost at Sea written by and published by . This book was released on 1983 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1984 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1985 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Information Output of the Langley Research Center written by and published by . This book was released on 1984 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government reports annual index written by and published by . This book was released on 199? with total page 1520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1984 with total page 1528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1984-03 with total page 1534 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Precise Underwater Acoustic Positioning Method Based on Phase Measurement written by Li Zhou and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Positioning an underwater object with respect to a reference point is required in diverse areas in ocean scientific and engineering undertakings, such as marine habitat monitoring, study of sedimentation processes, underwater searching and mapping, data collection, instrument placement and retrieval, and so on. Underwater acoustic positioning systems, including long baseline (LBL) systems, short baseline (SBL) systems, and ultra-short baseline (USBL) systems, are designed to operate from a reference point and employ external transducers or transducer arrays as aids for positioning. Traditional positioning methods rely on measuring of time-of-flight of an acoustic signal travelling from the target to the reference platform by means of the cross-correlation method. The positioning accuracy of LBL systems varies from a few centimeters to a few meters, depending on the operating range and working frequency. LBL systems provide a uniform positioning accuracy for a given transponder array setup, but they suffer the time-consuming instrument deployment on the seafloor, as well as the complicated operating procedures. SBL and USBL systems have relatively simple configurations. But their positioning accuracy is a function of water depth and operating range. To obtain absolute position accuracy, additional sensors such as the ship's gyro or a surface navigation system are needed. In this thesis, a novel positioning method is proposed which takes advantages of a tether cable between the reference platform and the target. This method conducts positioning via continuous phase measurement between a reference signal and the acoustic signal transmitted by the target to the reference platform. It is named the Positioning-based-on-PHase-Measurement method or PPHM method in short. Every 2? change in the phase difference between these two signals corresponds to a one-wavelength range increment along the radial direction from the target's initial position to its new position. If a receiver array is used, with at least two hydrophones, the target's bearing information can be also calculated by measuring the phases of the output signals from each of the array hydrophones. Under ideal conditions, the positioning error of the PPHM method is proportional to the phase measurement error. The PPHM method is very sensitive to changes in the underwater medium, such as sound speed variations, ocean currents and multipath interferences. Environmental fluctuations will degrade the positioning performance. These problems will be investigated and solutions will be proposed to minimize their effects. The PPHM method can be used to position an underwater moving object such as a remotely operated vehicle (ROV) or a bottom crawler. Also, it can be used to monitor the ocean currents speed variations over a path, or to monitor the movements of tectonic plates. The last two applications will be addressed in detail in this thesis, whereas the first one is very challenging and needs more work.
Download or read book Underwater Acoustic Positioning Systems written by P. H. Milne and published by . This book was released on 1983 with total page 304 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 Science & Business Media. This book was released on 2007-06-21 with total page 1179 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
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 A Precise Underwater Acoustic Positioning Method Based on Phase Measurement written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Positioning an underwater object with respect to a reference point is required in diverse areas in ocean scientific and engineering undertakings, such as marine habitat monitoring, study of sedimentation processes, underwater searching and mapping, data collection, instrument placement and retrieval, and so on. Underwater acoustic positioning systems, including long baseline (LBL) systems, short baseline (SBL) systems, and ultra-short baseline (USBL) systems, are designed to operate from a reference point and employ external transducers or transducer arrays as aids for positioning. Traditional positioning methods rely on measuring of time-of-flight of an acoustic signal travelling from the target to the reference platform by means of the cross-correlation method. The positioning accuracy of LBL systems varies from a few centimeters to a few meters, depending on the operating range and working frequency. LBL systems provide a uniform positioning accuracy for a given transponder array setup, but they suffer the time-consuming instrument deployment on the seafloor, as well as the complicated operating procedures. SBL and USBL systems have relatively simple configurations. But their positioning accuracy is a function of water depth and operating range. To obtain absolute position accuracy, additional sensors such as the ship's gyro or a surface navigation system are needed. In this thesis, a novel positioning method is proposed which takes advantages of a tether cable between the reference platform and the target. This method conducts positioning via continuous phase measurement between a reference signal and the acoustic signal transmitted by the target to the reference platform. It is named the Positioning-based-on-PHase-Measurement method or PPHM method in short. Every 2 change in the phase difference between these two signals corresponds to a one-wavelength range increment along the radial direction from the targets initial position to its new position. If a receive.
Download or read book Underwater Acoustic Sensor Networks written by Yang Xiao and published by CRC Press. This book was released on 2010-05-19 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detailed review of underwater channel characteristics, Underwater Acoustic Sensor Networks investigates the fundamental aspects of underwater communication. Prominent researchers from around the world consider contemporary challenges in the development of underwater acoustic sensor networks (UW-ASNs) and introduce a cross-layer approach for effec
Download or read book Underwater Medicine and Related Sciences written by Margaret F. Werts and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is the third annotated bibliography on this subject area to be compiled by these authors. The first, published by Gordon and Breach, Science Publishers, in 1971, was entitled AN ANNOTATED BIBLIOGRAPHY ON DIVING AND SUBMARINE MEDICINE. It covered material published during the 1960's. The second volume, entitled UNDERWATER MEDICINE AND RELATED SCIENCES: A GUIDE TO THE LITERATURE, published in 1973 by Plenum Press, covered primarily material published during 1970 and 1971, with some material from 1968 and 1969. The present volume covers material published during 1972 and 1973, but here again some earlier material has been included. The purpose of these annotated bibliographies is to make available a large proportion of the published material, in abstract form, indexed in such a manner as to make it possible to compile a reasonably complete annotated bibliography on any specific subject area in the field. It is possible thus to learn where the work is being done, by whom, and how extensively. Also, it becomes obvious what areas of research are lacking or inadequate. These specific searches can also form a background of reference material on which to base further research, or from which to write monographs or state-of-the-art surveys. Papers, articles and reports listed here are in most cases readily available.
Download or read book Proceedings written by and published by . This book was released on 1970 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Petroleum Abstracts written by and published by . This book was released on 1972 with total page 1038 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estuarine and Coastal Hydrography and Sediment Transport written by R. J. Uncles and published by Cambridge University Press. This book was released on 2017-08-17 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: A practical guide to the latest techniques to measure sediments, seabed, water and transport mechanisms in estuaries and coastal waters. Covering a broad range of topics, enough background is included to explain how each technology functions. A review of recent fieldwork experiments demonstrates how modern methods apply in real-life scenarios.
