Coupled mode solution for a cylindrically symmetric oceanic waveguide with a range and depth dependent refractive index and a time varying rough sea surface

1983 ◽  
Vol 73 (3) ◽  
pp. 800-805 ◽  
Author(s):  
C. Allan Boyles
Keyword(s):  
Refractive Index ◽  
Sea Surface ◽  
Time Varying ◽  
Oceanic Waveguide ◽  
Coupled Mode ◽  
Cylindrically Symmetric ◽  
Mode Solution ◽  
Rough Sea Surface ◽  
Rough Sea

Investigation of Sea Surface Effect on Shallow Water Reverberation by Coupled Mode Method

2017 ◽  
Vol 25 (02) ◽  
pp. 1750017 ◽  
Author(s):  
Bo Gao ◽  
Ning Wang ◽  
Hao Zhong Wang
Keyword(s):  
Shallow Water ◽  
Long Range ◽  
Surface Effect ◽  
Sea Surface ◽  
Surface Scattering ◽  
Sea State ◽  
Coupled Mode ◽  
Mode Method ◽  
Rough Sea Surface ◽  
Rough Sea

The effects of rough sea surface on the long-range bottom reverberation in shallow seas are studied by the coupled mode reverberation theory. The scattering effect caused by irregular rough sea surface is described by couple coefficients. The decaying rules of long-range bottom reverberation level are simulated at different sea states, and the rough sea surface effect on the coherence of distant bottom reverberation is also discussed. It is indicated that irregular upper boundary has changed the propagation effect of the shallow water waveguide, and bottom reverberation, which is dominated among other kinds of reverberation in shallow water, is affected by the sea surface scattering as the increasing sea state. Compared with other literatures, the emphasis of this paper is to present the mechanism of rough sea surface scattering by describing the transfer of energy between different modes, and the details of energy transitions between different modes which are caused by sea surface scattering are presented for different sea states. With the increasing sea state, stronger mode coupling caused by surface scattering would affect the intensity and its space coherence of bottom reverberation obviously.

Modeling scattering effects from time-varying sea surface based on acoustic reciprocity

Geophysics ◽  
2018 ◽  
Vol 83 (2) ◽  
pp. T49-T68 ◽  
Author(s):  
Elsa Cecconello ◽  
Endrias G. Asgedom ◽  
Okwudili C. Orji ◽  
Morten W. Pedersen ◽  
Walter Söllner
Keyword(s):  
Weather Conditions ◽  
Sea Surface ◽  
Time Varying ◽  
Flat Mirror ◽  
Sea Surface Effects ◽  
Marine Seismic ◽  
Rough Sea Surface ◽  
Frequency Domain Approach ◽  
The Impact ◽  
Rough Sea

In marine seismic processing, the sea surface is often considered a flat mirror; hence, the effects of different weather conditions during the acquisition are largely ignored. However, studies have shown that rough sea-surface ghosts can severely damage the 4D signal, if not handled properly in data processing. To account for realistic sea-surface effects in processing, the impact of time-varying rough sea surfaces needs to be studied. We derive a method for modeling source and receiver ghosts from the time-varying rough sea surface and their interaction with subsurface reflections. This method is based on acoustic reciprocity and leads to integral equations of nonstationary wavefields. These modeling equations can also serve as a basis for investigating source and receiver deghosting methods for time-varying rough sea surfaces. Our developed modeling algorithm is validated against a frequency-domain approach for a “frozen” rough sea surface. For a moving simple sea surface, the Doppler shift produced by our method is in very good agreement with the analytical solution. Using a Pierson-Moskowitz spectrum, we derive a time-varying rough sea surface and model the receiver ghost, the source ghost, and the source-receiver ghost for the subsurface primary reflections of a heterogeneous geologic model. The results highlight that the source and receiver ghost interactions with a time-varying sea surface differently affect the subsurface reflections, and these effects can significantly impact the seismic repeatability of 4D studies.

Two-Position HF Scattering from the Rough Sea Surface. II. Experiment

2005 ◽  
Vol 64 (12) ◽  
pp. 1003-1016
Author(s):  
A. S. Bryukhovetsky ◽  
Yu. M. Yampolski ◽  
A. S. Kashcheyev ◽  
S. B. Kashcheyev ◽  
A. B. Koloskov ◽  
...  
Keyword(s):  
Sea Surface ◽  
Rough Sea Surface ◽  
Rough Sea

Two-Position HF Scattering from the Rough Sea Surface. I. Theory

2005 ◽  
Vol 64 (12) ◽  
pp. 991-1001
Author(s):  
A. S. Bryukhovetsky ◽  
Yu. M. Yampolski ◽  
A. S. Kashcheyev ◽  
S. B. Kashcheyev
Keyword(s):  
Sea Surface ◽  
Rough Sea Surface ◽  
Rough Sea
Sign in / Sign up

Export Citation Format

Share Document