Results 231 to 240 of about 27,676 (260)

Approximate methods for reflection from solid bottoms.

The Journal of the Acoustical Society of America, 1992
The acoustic reflection coefficient for a solid ocean bottom can be well approximated by assuming an ‘‘equivalent fluid’’ bottom of suitably chosen parameters. The density and attenuation of the equivalent fluid are different from the corresponding parameters of the solid.
Z. Y. Zhang, C. T. Tindle
openaire   +1 more source

Marine Sediment Attenuation and Ocean-Bottom-Reflected Sound

The Journal of the Acoustical Society of America, 1964
The attenuation of sound in marine sediments is shown to depend on the first power of the frequency for a range of 100–1000 cps, and the relation between sediment attenuation and ocean-bottom reflectivity is discussed. The reflection process is approximated by a three-layer fluid model, with attenuation in the second and third layers.
openaire   +1 more source

Studies of the ocean-bottom reflection coefficient at angles of total internal reflection

Acoustical Physics, 2002
For practical-purpose studies in underwater acoustics, a new method is proposed to determine the bottom reflection coefficient on the basis of multiple bottom-surface reflections. The method allows one to obtain the angular dependence of the bottom reflection coefficient at grazing angles from several degrees to several tens of degrees in the audio and
openaire   +1 more source

An Inversion Method for Obtaining Bottom Reflection Loss

1994
The direct problem in ocean acoustics is to predict the emission or propagation of sound on the basis of a known attribute of sources or media. The inversion or indirect problem is to deduce the features of sources or media from the sound that has propagated to the hydrophone.
Wang Qin, Zhang Ren-he
openaire   +1 more source

Negative bottom loss, critical-angle shift, and the interpretation of the bottom reflection coefficient

The Journal of the Acoustical Society of America, 1977
The determination of the acoustical properties of the ocean bottom is a formidable task. One method is the seismic reflection method. Some of the limitations inherent in the interpretation of the reflected field are described. These include the dependence of the measurement on the complete geometry of the experiment, the occurrence of negative bottom ...
openaire   +1 more source

Diffuse Reflection and Transmission in a Finite Inhomogeneous Atmosphere with a Reflecting Bottom Surface

Publications of the Astronomical Society of Japan, 1967
Abstract In a finite inhomogeneous, plane-parallel and isotropically-scattering atmosphere, whose lower surface reflects light according to Lambert’s law, the problem of diffuse reflection and transmission of parallel rays incident on the upper surface in a specified direction is exactly studied.
openaire   +1 more source

Reflection of Sound from Coastal Sea Bottoms

The Journal of the Acoustical Society of America, 1948
An experimental method has been developed for measuring the reflection coefficient of the ocean bottom for supersonic sound at grazing incidence. In this method the geometry is controlled so that the resultant of the direct and reflected rays passes through consecutive maxima and minima at the hydrophone.
openaire   +1 more source

The Reflectivity of Two Bottom Areas as Measured by Total Energy Reflection Coefficients

The Journal of the Acoustical Society of America, 1967
In a paper presented at the 72nd meeting of the Acoustical Society of America, the author discussed the high variability in the peak amplitude bottom reflection coefficients obtained using pulsed CW signals over an abyssal plain area. These results led to an investigation into the use of a reflected-to-incident energy ratio as a more suitable ...
openaire   +1 more source

Detection of Coral Bleaching in Oceanic Islands Using Normalized Bottom Reflectance Change Index From Multispectral Satellite Imagery

IEEE Geoscience and Remote Sensing Letters, 2023
Juan Wang, Wenting Cao, Huaguo Zhang
exaly  

Bottom Simulating Reflections in Antarctica

2022
openaire   +1 more source