Results 221 to 230 of about 27,676 (260)

Theoretical reflectivity and simulation of reflection from the ocean bottom

The Journal of the Acoustical Society of America, 1978
The boundary value problem to be solved in computing the reflectivity of a solid, viscoelastic, ocean bottom can be formulated as a matrix differential equation with variable coefficients. In the Thomson-Haskell techniques a solution is found by assuming the coefficients (elastic parameters) are constant over a certain depth range (a layer).
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Normal-incidence bottom and sub-bottom reflection in the Canada basin of the Arctic Ocean

The Journal of the Acoustical Society of America
The normal-incidence reflection coefficient of a patch of seabed in the Arctic Ocean was analyzed using the signal from a source colocated with a vertical line array. A mooring in the Canada Basin of the Arctic Ocean in approximately 4000 m water depth, contained a sound source 54.7 m below the water surface and a vertical receiving array below it. The
Nicholas P. Chotiros, Matthew Dzieciuch
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Effects of bottom reflectivity on volume (fish) and bottom backscattering in shallow water

Proceedings of OCEANS'94, 2002
Reverberation measurements in shallow water made with fixed source and receiver arrays (D. Weston, 1971) demonstrated that scattering from bladder-bearing fish can dominate backscatter from long ranges in shallow water environments at frequencies of 1 and 2 kHz. In this work, estimates of monostatic scattering levels due to both bottom and volume (fish)
O. Diachok, J.R. Preston
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Reflection of long waves from a “nonreflecting” bottom profile

Fluid Dynamics, 2008
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Didenkulova, I. I., Zahibo, N., Pelinovsky, E. N.   +2 more
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A Perspective on Bottom Reflectivity and Backscattering

1980
A review of available data and description of observed effects permit an assessment of progress made since the 1970 SACLANT Conference on this same topic. Physical models have been developed and refined which can both explain the observations and serve as a basis for predictions.
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Surface-Reflected/Bottom-Reflected Ray Transmissions in a Divergent Channel

The Journal of the Acoustical Society of America, 1968
Surface-reflected/bottom-reflected ray transmissions in a divergent channel are studied when the sound velocity decreases linearly with depth. The sound source and receiving point are located on the bottom. Under certain simplifying assumptions, ray geometry is examined, and conditions are given under which a ray is surface reflected, refracted, or a ...
Melvin J. Jacobson, J. Thomas Warfield
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Interference in Reflections from the Ocean Bottom and Subbottom

The Journal of the Acoustical Society of America, 1961
A strong interference pattern has been observed in the reflection of monochromatic pings from the ocean bottom. The experiment was performed in the Gulf of Mexico at 24°16′N, 85°15′W. The acoustic pings had a frequency of 120.5 cps and a length of 0.12 sec and were repeated every sec. The transmitter was at a depth of 75 ft and the receiver at 3000 ft.
M. Vertner Brown, James Ricard
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Spectra and Waveforms of Bottom-Reflected Pulses

The Journal of the Acoustical Society of America, 1966
A mathematical model considering reflection as a reradiation phenomenon has been constructed. The model allows computation of the spectrum and waveform of a reflected pulse in terms of the incident plane-wave pulse or its spectrum, the reradiation characteristics of the reflector, the incident direction, and the reradiation direction. Bottom reflection
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Reflectivity of the ocean bottom at low frequency

The Journal of the Acoustical Society of America, 1978
The theoretical reflectivity of the ocean bottom estimated from a model composed of fluid sediment layers is misleading because the effects of shear propagation are ignored. Reflectivity computations which include the effects of shear may be made using Thomson–Haskell matrix theory.
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Reflection of Sound from Coastal Bottoms

The Journal of the Acoustical Society of America, 1959
A number of sea trips were made during the summer of 1950 and through the spring of 1951 to measure 1-kc sound-reflection losses over several bottoms as a function of the grazing angle. The results agree with Rayleigh's expressions as modified by R. W. Morse to allow for the attenuation in the bottom.
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