Eastern Arctic SURSAT SAR Ice Experiment: Radar Signatures of Sea Ice Features.
Evaluation of X- and L-band steep angle synthetic aperture radar (SAR) sea ice imagery taken in Baffin Bay and Davis Strait in April 1979 has shown that description and discrimination of first-season ice types can be difficult because of ambiguous radar returns. Ambiguous returns seen on X-band rada...
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ftdtic:ADA090629 2023-05-15T15:01:57+02:00 Eastern Arctic SURSAT SAR Ice Experiment: Radar Signatures of Sea Ice Features. Ketchum,R D , Jr Farmer,L Dennis NAVAL OCEAN RESEARCH AND DEVELOPMENT ACTIVITY NSTL STATION MS 1980-08 text/html http://www.dtic.mil/docs/citations/ADA090629 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA090629 en eng http://www.dtic.mil/docs/citations/ADA090629 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Snow Ice and Permafrost Active & Passive Radar Detection & Equipment Unmanned Spacecraft *SYNTHETIC APERTURE RADAR *SNOW *SEA WATER *RADAR SIGNATURES *SEA ICE *ICEBERGS INTERFACES SURFACE ROUGHNESS BACKSCATTERING ICE MEDIA REFLECTIVITY X BAND ARCTIC REGIONS BAYS L BAND SCIENTIFIC SATELLITES STRAITS Imagery(Sea ice) Angles(Steep) Ice(First season) Baffin Bay Davis Strait Cover(Snow) Ridges(Ice) SURSAT project Forecasting(Ice) Text 1980 ftdtic 2016-02-20T18:47:23Z Evaluation of X- and L-band steep angle synthetic aperture radar (SAR) sea ice imagery taken in Baffin Bay and Davis Strait in April 1979 has shown that description and discrimination of first-season ice types can be difficult because of ambiguous radar returns. Ambiguous returns seen on X-band radar imagery are attributed to snow cover. The data have indicated that changes in snow properties due to melting and refreezing cause development of a highly reflective medium to the 3 cm X-band radar. The 25 cm L-band radar is not noticeably affected by the observed phenomena, thus correlation of coincident X- and L-band imagery often resolves interpretation ambiguities on the X-band imagery caused by the snow effects. The data suggest that L-band radar energy often penetrates the ice and that subsurface returns are received. These returns also produce ambiguities in interpretation. Apparent smooth surfaces do not show this effect, but rough surfaces which have widely different roughness densities may produce apparently equal backscatter of L-band radar. Ice ridge identification and discrimination was often poor due to the obscuring effects of background clutter associated with the above-suggested backscattering phenomena. Small ridge sizes versus system resolution and steep angles of incidence also reduce ridge identification capabilities. Some icebergs produced time-delayed L-band signals, indicating internal reflections within the iceberg. Iceberg/water interface reflections rather than volume scattering are indicated. L-band radar cannot be depended upon for iceberg identification, since icebergs may be only partially imaged or not imaged at all by this frequency. Text Arctic Baffin Bay Baffin Bay Baffin Davis Strait Ice Iceberg* permafrost Sea ice Defense Technical Information Center: DTIC Technical Reports database Arctic Baffin Bay |
institution |
Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Snow Ice and Permafrost Active & Passive Radar Detection & Equipment Unmanned Spacecraft *SYNTHETIC APERTURE RADAR *SNOW *SEA WATER *RADAR SIGNATURES *SEA ICE *ICEBERGS INTERFACES SURFACE ROUGHNESS BACKSCATTERING ICE MEDIA REFLECTIVITY X BAND ARCTIC REGIONS BAYS L BAND SCIENTIFIC SATELLITES STRAITS Imagery(Sea ice) Angles(Steep) Ice(First season) Baffin Bay Davis Strait Cover(Snow) Ridges(Ice) SURSAT project Forecasting(Ice) |
spellingShingle |
Snow Ice and Permafrost Active & Passive Radar Detection & Equipment Unmanned Spacecraft *SYNTHETIC APERTURE RADAR *SNOW *SEA WATER *RADAR SIGNATURES *SEA ICE *ICEBERGS INTERFACES SURFACE ROUGHNESS BACKSCATTERING ICE MEDIA REFLECTIVITY X BAND ARCTIC REGIONS BAYS L BAND SCIENTIFIC SATELLITES STRAITS Imagery(Sea ice) Angles(Steep) Ice(First season) Baffin Bay Davis Strait Cover(Snow) Ridges(Ice) SURSAT project Forecasting(Ice) Ketchum,R D , Jr Farmer,L Dennis Eastern Arctic SURSAT SAR Ice Experiment: Radar Signatures of Sea Ice Features. |
topic_facet |
Snow Ice and Permafrost Active & Passive Radar Detection & Equipment Unmanned Spacecraft *SYNTHETIC APERTURE RADAR *SNOW *SEA WATER *RADAR SIGNATURES *SEA ICE *ICEBERGS INTERFACES SURFACE ROUGHNESS BACKSCATTERING ICE MEDIA REFLECTIVITY X BAND ARCTIC REGIONS BAYS L BAND SCIENTIFIC SATELLITES STRAITS Imagery(Sea ice) Angles(Steep) Ice(First season) Baffin Bay Davis Strait Cover(Snow) Ridges(Ice) SURSAT project Forecasting(Ice) |
description |
Evaluation of X- and L-band steep angle synthetic aperture radar (SAR) sea ice imagery taken in Baffin Bay and Davis Strait in April 1979 has shown that description and discrimination of first-season ice types can be difficult because of ambiguous radar returns. Ambiguous returns seen on X-band radar imagery are attributed to snow cover. The data have indicated that changes in snow properties due to melting and refreezing cause development of a highly reflective medium to the 3 cm X-band radar. The 25 cm L-band radar is not noticeably affected by the observed phenomena, thus correlation of coincident X- and L-band imagery often resolves interpretation ambiguities on the X-band imagery caused by the snow effects. The data suggest that L-band radar energy often penetrates the ice and that subsurface returns are received. These returns also produce ambiguities in interpretation. Apparent smooth surfaces do not show this effect, but rough surfaces which have widely different roughness densities may produce apparently equal backscatter of L-band radar. Ice ridge identification and discrimination was often poor due to the obscuring effects of background clutter associated with the above-suggested backscattering phenomena. Small ridge sizes versus system resolution and steep angles of incidence also reduce ridge identification capabilities. Some icebergs produced time-delayed L-band signals, indicating internal reflections within the iceberg. Iceberg/water interface reflections rather than volume scattering are indicated. L-band radar cannot be depended upon for iceberg identification, since icebergs may be only partially imaged or not imaged at all by this frequency. |
author2 |
NAVAL OCEAN RESEARCH AND DEVELOPMENT ACTIVITY NSTL STATION MS |
format |
Text |
author |
Ketchum,R D , Jr Farmer,L Dennis |
author_facet |
Ketchum,R D , Jr Farmer,L Dennis |
author_sort |
Ketchum,R D , Jr |
title |
Eastern Arctic SURSAT SAR Ice Experiment: Radar Signatures of Sea Ice Features. |
title_short |
Eastern Arctic SURSAT SAR Ice Experiment: Radar Signatures of Sea Ice Features. |
title_full |
Eastern Arctic SURSAT SAR Ice Experiment: Radar Signatures of Sea Ice Features. |
title_fullStr |
Eastern Arctic SURSAT SAR Ice Experiment: Radar Signatures of Sea Ice Features. |
title_full_unstemmed |
Eastern Arctic SURSAT SAR Ice Experiment: Radar Signatures of Sea Ice Features. |
title_sort |
eastern arctic sursat sar ice experiment: radar signatures of sea ice features. |
publishDate |
1980 |
url |
http://www.dtic.mil/docs/citations/ADA090629 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA090629 |
geographic |
Arctic Baffin Bay |
geographic_facet |
Arctic Baffin Bay |
genre |
Arctic Baffin Bay Baffin Bay Baffin Davis Strait Ice Iceberg* permafrost Sea ice |
genre_facet |
Arctic Baffin Bay Baffin Bay Baffin Davis Strait Ice Iceberg* permafrost Sea ice |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA090629 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
_version_ |
1766333955393454080 |