Reflection and Scattering of Acoustic Rays Computed for Parabolic Ice Keel Models.
Coefficients are computed for ray reflection and scattering from a model of a set of keels. The model is a collection of parallel ice keels that are of parabolic cross section. The size of the keels and the spacing between them are drawn from random distributions. The keels are also widened by a ran...
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ftdtic:ADA193898 2023-05-15T14:57:42+02:00 Reflection and Scattering of Acoustic Rays Computed for Parabolic Ice Keel Models. Gordon, D F NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA 1988-04 text/html http://www.dtic.mil/docs/citations/ADA193898 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA193898 en eng http://www.dtic.mil/docs/citations/ADA193898 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Acoustics Physical and Dynamic Oceanography *SEA ICE *ACOUSTIC SCATTERING *UNDERWATER ACOUSTICS ANGLES ARCTIC REGIONS BACKSCATTERING COEFFICIENTS CROSS SECTIONS DISTRIBUTION ELASTIC PROPERTIES GRAZING LONG RANGE(TIME) PARABOLAS SLOPE SOLIDS SOUND TRANSMISSION STRENGTH(GENERAL) SURFACE PROPERTIES THEORY ACOUSTIC REFLECTION Ice keels PE61152N WU711ZT69 Text 1988 ftdtic 2016-02-19T11:12:53Z Coefficients are computed for ray reflection and scattering from a model of a set of keels. The model is a collection of parallel ice keels that are of parabolic cross section. The size of the keels and the spacing between them are drawn from random distributions. The keels are also widened by a random factor to simulate oblique incidence on nonparallel keels. Rays are permitted to reflect from and refract through keels according to the interface properties between fluids and elastic solids. A large number of rays are directed toward the keel model and, upon emergence, are sorted into angular bins to determine scattering strength versus direction. Scattering coefficients have a dominant lobe near the secular direction. This is shown to result from the shape of the curve of reflection versus grazing angle. Very little backscatter occurs, a result of the limited slope angle of the parabolic keel models. Keywords: Arctic acoustics; Acoustic propagation; Ray theory; Sea ice; Reflection coefficients; Scattering coefficients; Ice keels. Text Arctic Sea ice Defense Technical Information Center: DTIC Technical Reports database Arctic |
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Open Polar |
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Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Acoustics Physical and Dynamic Oceanography *SEA ICE *ACOUSTIC SCATTERING *UNDERWATER ACOUSTICS ANGLES ARCTIC REGIONS BACKSCATTERING COEFFICIENTS CROSS SECTIONS DISTRIBUTION ELASTIC PROPERTIES GRAZING LONG RANGE(TIME) PARABOLAS SLOPE SOLIDS SOUND TRANSMISSION STRENGTH(GENERAL) SURFACE PROPERTIES THEORY ACOUSTIC REFLECTION Ice keels PE61152N WU711ZT69 |
spellingShingle |
Acoustics Physical and Dynamic Oceanography *SEA ICE *ACOUSTIC SCATTERING *UNDERWATER ACOUSTICS ANGLES ARCTIC REGIONS BACKSCATTERING COEFFICIENTS CROSS SECTIONS DISTRIBUTION ELASTIC PROPERTIES GRAZING LONG RANGE(TIME) PARABOLAS SLOPE SOLIDS SOUND TRANSMISSION STRENGTH(GENERAL) SURFACE PROPERTIES THEORY ACOUSTIC REFLECTION Ice keels PE61152N WU711ZT69 Gordon, D F Reflection and Scattering of Acoustic Rays Computed for Parabolic Ice Keel Models. |
topic_facet |
Acoustics Physical and Dynamic Oceanography *SEA ICE *ACOUSTIC SCATTERING *UNDERWATER ACOUSTICS ANGLES ARCTIC REGIONS BACKSCATTERING COEFFICIENTS CROSS SECTIONS DISTRIBUTION ELASTIC PROPERTIES GRAZING LONG RANGE(TIME) PARABOLAS SLOPE SOLIDS SOUND TRANSMISSION STRENGTH(GENERAL) SURFACE PROPERTIES THEORY ACOUSTIC REFLECTION Ice keels PE61152N WU711ZT69 |
description |
Coefficients are computed for ray reflection and scattering from a model of a set of keels. The model is a collection of parallel ice keels that are of parabolic cross section. The size of the keels and the spacing between them are drawn from random distributions. The keels are also widened by a random factor to simulate oblique incidence on nonparallel keels. Rays are permitted to reflect from and refract through keels according to the interface properties between fluids and elastic solids. A large number of rays are directed toward the keel model and, upon emergence, are sorted into angular bins to determine scattering strength versus direction. Scattering coefficients have a dominant lobe near the secular direction. This is shown to result from the shape of the curve of reflection versus grazing angle. Very little backscatter occurs, a result of the limited slope angle of the parabolic keel models. Keywords: Arctic acoustics; Acoustic propagation; Ray theory; Sea ice; Reflection coefficients; Scattering coefficients; Ice keels. |
author2 |
NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA |
format |
Text |
author |
Gordon, D F |
author_facet |
Gordon, D F |
author_sort |
Gordon, D F |
title |
Reflection and Scattering of Acoustic Rays Computed for Parabolic Ice Keel Models. |
title_short |
Reflection and Scattering of Acoustic Rays Computed for Parabolic Ice Keel Models. |
title_full |
Reflection and Scattering of Acoustic Rays Computed for Parabolic Ice Keel Models. |
title_fullStr |
Reflection and Scattering of Acoustic Rays Computed for Parabolic Ice Keel Models. |
title_full_unstemmed |
Reflection and Scattering of Acoustic Rays Computed for Parabolic Ice Keel Models. |
title_sort |
reflection and scattering of acoustic rays computed for parabolic ice keel models. |
publishDate |
1988 |
url |
http://www.dtic.mil/docs/citations/ADA193898 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA193898 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Sea ice |
genre_facet |
Arctic Sea ice |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA193898 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
_version_ |
1766329833144451072 |