Download or read book Acoustic Fluctuations Due to Shallow Water Thermal Microstructure written by James Burgess Hagen and published by . This book was released on 1974 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simultaneous measurements of waves, orthogonal water particle velocities, temperature, conductivity and acoustic phase and amplitude measurements at 20 and 40 kHz over horizontal and vertical, 2m paths were made at the Navel Underwater Center oceanographic tower, San Diego in April 1974. Four stochastic models for acoustic propagation including geometric, Born, Rytov and Debye approximation models were tested. Taylor thermal microscales from spatial correlation analyses determined vertically across the thermocline varied from 6.8 to 178 cm. Temporal stochastic analyses showed horizontal acoustic path losses were ten times vertical losses because of diffraction effects.
Download or read book Acoustic Fluctuations Due to Shallow Thermal Microstructure written by James Burgess Hagen and published by . This book was released on 1974 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Fluctuations Due to Shallow Thermal Microstructure written by and published by . This book was released on 1974 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Fluctuations Due to Shallow Water Internal Waves written by D. E. Weston and published by . This book was released on 1972 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oscillations of up to 20 dB in level with total duration about 1 1/2 hours have been extensively seen in acoustic propagation experiments, and are due to internal waves. The transmission distances varied from 2 to 23 km in water 35 m deep, with frequency typically about 2 kHz. The internal waves and their acoustic effects were virtually switched on and off through the tidal cycle. This is due to the delicate and varying balance between the vertical density gradient and the shear gradient which together determine the Richardson number. The oceanographic structure was complicated, and included strong horizontal temperature gradients. For 1964 and 1965 experiments in the eastern part of the working area the effects tended to occur near slack water (+ 2 hours relative to local high water) with periods of about 5 min and wavelengths apparently about 50 m. For 1967-1969 experiments in the western part the effects tended to occur near times of maximum flow ( -1 and +5 hours) with periods of about 20 min and wavelengths apparently about 500 m. Measurements from five other indicators of internal waves are included. (Author).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 456 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 NBS Special Publication written by and published by . This book was released on 1976 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Navy Symposium on Military Oceanography written by and published by . This book was released on 1964 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Symposium written by and published by . This book was released on 1964 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Symposium written by United States. Navy Symposium on Military Oceanography and published by . This book was released on 1964 with total page 502 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 1975-04 with total page 930 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydraulic Research in the United States and Canada 1974 written by Pauline H. Gurewitz and published by . This book was released on 1976 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics of Sound in Marine Sediments written by Lloyd Hampton and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: The phenomenon of sound transmissions through marine sediments is of extreme interest to both the United States civilian and Navy research communities. Both communities have conducted research within the field of this phenomenon approaching it from different perspectives. The academic research community has approached it as a technique for studying sedimentary and crustal structures of the ocean basins. The Navy research community has approached it as an additional variable in the predictability of sound trans mission through oceanic waters. In order to join these diverse talents, with the principal aim of bringing into sharp focus the state-of-the-science in the problems relating to the behavior of sound in marine sediments, the Office of Naval Research organized and sponsored an invited symposium on this subject. The papers published in this volume are the results of this symposium and mark the frontiers in the state-of-the-art. The symposia series were based on five research areas identified by ONR as being particularly suitable for critical review and for the appraisal of future research trends. These areas include: 1. Physics of Sound in Marine Sediments, 2. Physical and Engineering Properties of Deep-Sea Sediments, 3. The Role of Bottom Currents in Sea Floor Geological Processes, 4. Nephelometry and the Optical Properties of the Ocean I'laters, S. Natural Gases in Marine Sediments and Their Mode of Distribution. These five areas also form some of the research priorities of the ONR program in Marine Geology and Geophysics.
Download or read book Government Reports Announcements written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Predicting Sound Phase and Amplitude Fluctuations Due to Microstructure in the Upper Ocean written by Herman Medwin and published by . This book was released on 1973 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The temporal and spatial variations of the index of refraction cause fluctuations of sound phase and amplitude that can be completely understood only by defining the index in terms of the duration, location, range and time of the acoustic experiment. A truncated 'universal' spatial correlation function of the index has been derived from a simplified form of the Kolmogorov-Batchelor spectrum of temperature fluctuations in a homogeneous, isotropic medium. Although this correlation function is shown to be predictable simply from the depth of the experiment, it is of only limited validity with respect to large spatial lags. However, a Gaussian extrapolation of the 'universal' correlation function together with the standard deviation of the index provides simple useful predictions of the sound fluctuations due to temperature microstructure in the upper ocean. (Author).
Download or read book Principles and Applications of Underwater Sound written by United States. Office of Scientific Research and Development. National Defense Research Committee and published by . This book was released on 1969 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Principles and Applications of Underwater Sound Originally Issued as Summary Technical Report of Division 6 NDRC Vol 7 1946 Reprinted 1968 written by United States. Navy Department and published by . This book was released on 1969 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydraulic Research in the United States and Canada written by and published by . This book was released on 1972 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt:
