Propagation of Sound Generated on the Ice Surface into Water
One of the difficulties in taking underwater acoustic measurements at arctic ice camps is avoiding contamination of the measurements with camp- generated noise. To minimize this problem, investigators sometimes use a surface-laid cable system to place hydrophones well away from the camp. But how far...
Main Authors: | , |
---|---|
Other Authors: | |
Format: | Text |
Language: | English |
Published: |
1989
|
Subjects: | |
Online Access: | http://www.dtic.mil/docs/citations/ADA213583 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA213583 |
id |
ftdtic:ADA213583 |
---|---|
record_format |
openpolar |
spelling |
ftdtic:ADA213583 2023-05-15T14:58:36+02:00 Propagation of Sound Generated on the Ice Surface into Water Francois, R. E. Wen, T. WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB 1989-09 text/html http://www.dtic.mil/docs/citations/ADA213583 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA213583 en eng http://www.dtic.mil/docs/citations/ADA213583 Approved for public release; distribution is unlimited. DTIC AND NTIS Acoustics *AMBIENT NOISE *SEA ICE *CONTAMINATION *ACOUSTIC MEASUREMENT *NOISE POLLUTION *UNDERWATER ACOUSTICS DEPTH EMPLACEMENT SOUND TRANSMISSION SHORT RANGE(DISTANCE) LOSSES ACOUSTIC ABSORPTION HYDROPHONES ACOUSTIC FIELDS SHADOWS ARCTIC REGIONS FACILITIES ACOUSTIC WAVES MODELS MILITARY FACILITIES ACOUSTIC REFRACTION SIMULATION SOURCES PE62435N WUDN496433 Text 1989 ftdtic 2016-02-23T04:57:46Z One of the difficulties in taking underwater acoustic measurements at arctic ice camps is avoiding contamination of the measurements with camp- generated noise. To minimize this problem, investigators sometimes use a surface-laid cable system to place hydrophones well away from the camp. But how far from an ice camp must hydrophones be to ensure that camp-generated high- frequency interference (>1 kHz) is negligible? To answer this question, simulated camp noise was propagated from a source on top of the ice into the water below. Short-range measurements were then taken to locate the shadow zone under the ice where the acoustic energy from the source is negligible compared with the ambient noise field. This shadow zone was compared with sound propagation models that accounted for the refraction and absorption losses in the sea ice and in the water below. Inputs to the models were then adjusted to simulate different environmental conditions and longer ranges. Finally, conservative formulae were developed for determining the range and depth of hydrophone placement for a given reduction in the sound level from the source on the surface. Text Arctic Sea ice Defense Technical Information Center: DTIC Technical Reports database Arctic |
institution |
Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Acoustics *AMBIENT NOISE *SEA ICE *CONTAMINATION *ACOUSTIC MEASUREMENT *NOISE POLLUTION *UNDERWATER ACOUSTICS DEPTH EMPLACEMENT SOUND TRANSMISSION SHORT RANGE(DISTANCE) LOSSES ACOUSTIC ABSORPTION HYDROPHONES ACOUSTIC FIELDS SHADOWS ARCTIC REGIONS FACILITIES ACOUSTIC WAVES MODELS MILITARY FACILITIES ACOUSTIC REFRACTION SIMULATION SOURCES PE62435N WUDN496433 |
spellingShingle |
Acoustics *AMBIENT NOISE *SEA ICE *CONTAMINATION *ACOUSTIC MEASUREMENT *NOISE POLLUTION *UNDERWATER ACOUSTICS DEPTH EMPLACEMENT SOUND TRANSMISSION SHORT RANGE(DISTANCE) LOSSES ACOUSTIC ABSORPTION HYDROPHONES ACOUSTIC FIELDS SHADOWS ARCTIC REGIONS FACILITIES ACOUSTIC WAVES MODELS MILITARY FACILITIES ACOUSTIC REFRACTION SIMULATION SOURCES PE62435N WUDN496433 Francois, R. E. Wen, T. Propagation of Sound Generated on the Ice Surface into Water |
topic_facet |
Acoustics *AMBIENT NOISE *SEA ICE *CONTAMINATION *ACOUSTIC MEASUREMENT *NOISE POLLUTION *UNDERWATER ACOUSTICS DEPTH EMPLACEMENT SOUND TRANSMISSION SHORT RANGE(DISTANCE) LOSSES ACOUSTIC ABSORPTION HYDROPHONES ACOUSTIC FIELDS SHADOWS ARCTIC REGIONS FACILITIES ACOUSTIC WAVES MODELS MILITARY FACILITIES ACOUSTIC REFRACTION SIMULATION SOURCES PE62435N WUDN496433 |
description |
One of the difficulties in taking underwater acoustic measurements at arctic ice camps is avoiding contamination of the measurements with camp- generated noise. To minimize this problem, investigators sometimes use a surface-laid cable system to place hydrophones well away from the camp. But how far from an ice camp must hydrophones be to ensure that camp-generated high- frequency interference (>1 kHz) is negligible? To answer this question, simulated camp noise was propagated from a source on top of the ice into the water below. Short-range measurements were then taken to locate the shadow zone under the ice where the acoustic energy from the source is negligible compared with the ambient noise field. This shadow zone was compared with sound propagation models that accounted for the refraction and absorption losses in the sea ice and in the water below. Inputs to the models were then adjusted to simulate different environmental conditions and longer ranges. Finally, conservative formulae were developed for determining the range and depth of hydrophone placement for a given reduction in the sound level from the source on the surface. |
author2 |
WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB |
format |
Text |
author |
Francois, R. E. Wen, T. |
author_facet |
Francois, R. E. Wen, T. |
author_sort |
Francois, R. E. |
title |
Propagation of Sound Generated on the Ice Surface into Water |
title_short |
Propagation of Sound Generated on the Ice Surface into Water |
title_full |
Propagation of Sound Generated on the Ice Surface into Water |
title_fullStr |
Propagation of Sound Generated on the Ice Surface into Water |
title_full_unstemmed |
Propagation of Sound Generated on the Ice Surface into Water |
title_sort |
propagation of sound generated on the ice surface into water |
publishDate |
1989 |
url |
http://www.dtic.mil/docs/citations/ADA213583 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA213583 |
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/ADA213583 |
op_rights |
Approved for public release; distribution is unlimited. |
_version_ |
1766330734818099200 |