Effects of the Sea-Bed on Acoustic Propagation.
The sea-bed is known to be the controlling factor in low-frequency shallow-water acoustics. In lossy sea-beds waterborne sound is attenuated both the compressional-wave attenuation in the bottom and by the coupling of sound into shear waves. The complicated frequency-dependent effect of the sea-bed...
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ftdtic:ADA137251 2023-05-15T17:28:44+02:00 Effects of the Sea-Bed on Acoustic Propagation. Akal,T Jensen,F B SACLANT ASW RESEARCH CENTRE LA SPEZIA (ITALY) 1983-11-15 text/html http://www.dtic.mil/docs/citations/ADA137251 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA137251 en eng http://www.dtic.mil/docs/citations/ADA137251 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Physical and Dynamic Oceanography Seismology Acoustics *Sound transmission *Transmission loss *Ocean bottom Bottom loss Shallow water Underwater acoustics Acoustic attenuation Coupling(Interaction) Acoustic velocity Broadband Mediterranean Sea North Atlantic Ocean Low frequency Sediments Sea water Waveguides Acoustic channels Seismic waves Wave propagation Interfaces NATO furnished Interface waves Propagation losses East North Atlantic Ocean Text 1983 ftdtic 2016-02-19T09:10:34Z The sea-bed is known to be the controlling factor in low-frequency shallow-water acoustics. In lossy sea-beds waterborne sound is attenuated both the compressional-wave attenuation in the bottom and by the coupling of sound into shear waves. The complicated frequency-dependent effect of the sea-bed on propagation has been studied theoretically, and it is found that bottom loss increases with decreasing frequency down to near the cut-off frequency of the ocean waveguide, at which frequency seismic propagation by interface waves on the sea floor becomes more important than acoustic propagation. It is also found that while propagation losses in the water column are strongly dependent on bottom type, a feature such as the optimum frequency of acoustic propagation in the water column is only slightly dependent on sea-bed properties. Broadband propagation data collected in different areas of the Mediterranean Sea and the eastern North Atlantic are shown to support these theoretical findings. (Author) Text North Atlantic Defense Technical Information Center: DTIC Technical Reports database |
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Defense Technical Information Center: DTIC Technical Reports database |
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ftdtic |
language |
English |
topic |
Physical and Dynamic Oceanography Seismology Acoustics *Sound transmission *Transmission loss *Ocean bottom Bottom loss Shallow water Underwater acoustics Acoustic attenuation Coupling(Interaction) Acoustic velocity Broadband Mediterranean Sea North Atlantic Ocean Low frequency Sediments Sea water Waveguides Acoustic channels Seismic waves Wave propagation Interfaces NATO furnished Interface waves Propagation losses East North Atlantic Ocean |
spellingShingle |
Physical and Dynamic Oceanography Seismology Acoustics *Sound transmission *Transmission loss *Ocean bottom Bottom loss Shallow water Underwater acoustics Acoustic attenuation Coupling(Interaction) Acoustic velocity Broadband Mediterranean Sea North Atlantic Ocean Low frequency Sediments Sea water Waveguides Acoustic channels Seismic waves Wave propagation Interfaces NATO furnished Interface waves Propagation losses East North Atlantic Ocean Akal,T Jensen,F B Effects of the Sea-Bed on Acoustic Propagation. |
topic_facet |
Physical and Dynamic Oceanography Seismology Acoustics *Sound transmission *Transmission loss *Ocean bottom Bottom loss Shallow water Underwater acoustics Acoustic attenuation Coupling(Interaction) Acoustic velocity Broadband Mediterranean Sea North Atlantic Ocean Low frequency Sediments Sea water Waveguides Acoustic channels Seismic waves Wave propagation Interfaces NATO furnished Interface waves Propagation losses East North Atlantic Ocean |
description |
The sea-bed is known to be the controlling factor in low-frequency shallow-water acoustics. In lossy sea-beds waterborne sound is attenuated both the compressional-wave attenuation in the bottom and by the coupling of sound into shear waves. The complicated frequency-dependent effect of the sea-bed on propagation has been studied theoretically, and it is found that bottom loss increases with decreasing frequency down to near the cut-off frequency of the ocean waveguide, at which frequency seismic propagation by interface waves on the sea floor becomes more important than acoustic propagation. It is also found that while propagation losses in the water column are strongly dependent on bottom type, a feature such as the optimum frequency of acoustic propagation in the water column is only slightly dependent on sea-bed properties. Broadband propagation data collected in different areas of the Mediterranean Sea and the eastern North Atlantic are shown to support these theoretical findings. (Author) |
author2 |
SACLANT ASW RESEARCH CENTRE LA SPEZIA (ITALY) |
format |
Text |
author |
Akal,T Jensen,F B |
author_facet |
Akal,T Jensen,F B |
author_sort |
Akal,T |
title |
Effects of the Sea-Bed on Acoustic Propagation. |
title_short |
Effects of the Sea-Bed on Acoustic Propagation. |
title_full |
Effects of the Sea-Bed on Acoustic Propagation. |
title_fullStr |
Effects of the Sea-Bed on Acoustic Propagation. |
title_full_unstemmed |
Effects of the Sea-Bed on Acoustic Propagation. |
title_sort |
effects of the sea-bed on acoustic propagation. |
publishDate |
1983 |
url |
http://www.dtic.mil/docs/citations/ADA137251 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA137251 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA137251 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
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1766121593330728960 |