Radar Detection of Ice Wedges in Alaska
The radar signatures of ice wedges and wedge-like structures have been investigated for a variety of soil conditions. The radar used for this study emitted short sinusoidal pulses of about 10-ns duration with an approximate center frequency of 150 MHz. Most of the ice wedges existed at depths of abo...
Main Authors: | , , |
---|---|
Other Authors: | |
Format: | Text |
Language: | English |
Published: |
1982
|
Subjects: | |
Online Access: | http://www.dtic.mil/docs/citations/ADA124571 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA124571 |
id |
ftdtic:ADA124571 |
---|---|
record_format |
openpolar |
spelling |
ftdtic:ADA124571 2023-05-15T16:36:42+02:00 Radar Detection of Ice Wedges in Alaska Arcone,Steven A Sellmann,Paul V Delaney,Allan J COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH 1982-12 text/html http://www.dtic.mil/docs/citations/ADA124571 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA124571 en eng http://www.dtic.mil/docs/citations/ADA124571 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Snow Ice and Permafrost Active & Passive Radar Detection & Equipment *BOUNDARIES *LAND ICE *RADAR SCANNING DETECTION LITERATURE SURVEYS ALASKA SAND DEPTH SOILS PROFILES ICE RADAR REFLECTIONS THAWING WEDGES RADAR SIGNATURES SILT PERMAFROST HYPERBOLAS Ice wedges PE62730A AST42 WU11 Text 1982 ftdtic 2016-02-20T21:48:32Z The radar signatures of ice wedges and wedge-like structures have been investigated for a variety of soil conditions. The radar used for this study emitted short sinusoidal pulses of about 10-ns duration with an approximate center frequency of 150 MHz. Most of the ice wedges existed at depths of about 1 m in a variety of silty and sandy soils with both frozen and thawed active layers. The position of the wedges was usually identified from corresponding surface features. An artificial ice wedge in coarse-grained alluvium was also profiled as well as wedge-like structures of fine silt in a coarse-grained glacial outwash. All wedges and wedge-like structures produced a hyperbolic reflection profile except when an active layer of thawed, saturated silt was present which eliminated returns from the wedges. The peaks of the hyperbolas were sometimes masked by reflections from the permafrost table or other material interfaces, and multiple hyperbolas occurred at some sites. The dielectric constant of the host medium was often calculated from the linear portions of the hyperbolas and the results were verified by laboratory time domain reflectometry measurements performed on field samples. In some cases, hyperbolic profiles originated at several meters depth suggesting that deep ice wedges could be detected in areas of cold permafrost. Text Ice permafrost wedge* Alaska Defense Technical Information Center: DTIC Technical Reports database |
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 *BOUNDARIES *LAND ICE *RADAR SCANNING DETECTION LITERATURE SURVEYS ALASKA SAND DEPTH SOILS PROFILES ICE RADAR REFLECTIONS THAWING WEDGES RADAR SIGNATURES SILT PERMAFROST HYPERBOLAS Ice wedges PE62730A AST42 WU11 |
spellingShingle |
Snow Ice and Permafrost Active & Passive Radar Detection & Equipment *BOUNDARIES *LAND ICE *RADAR SCANNING DETECTION LITERATURE SURVEYS ALASKA SAND DEPTH SOILS PROFILES ICE RADAR REFLECTIONS THAWING WEDGES RADAR SIGNATURES SILT PERMAFROST HYPERBOLAS Ice wedges PE62730A AST42 WU11 Arcone,Steven A Sellmann,Paul V Delaney,Allan J Radar Detection of Ice Wedges in Alaska |
topic_facet |
Snow Ice and Permafrost Active & Passive Radar Detection & Equipment *BOUNDARIES *LAND ICE *RADAR SCANNING DETECTION LITERATURE SURVEYS ALASKA SAND DEPTH SOILS PROFILES ICE RADAR REFLECTIONS THAWING WEDGES RADAR SIGNATURES SILT PERMAFROST HYPERBOLAS Ice wedges PE62730A AST42 WU11 |
description |
The radar signatures of ice wedges and wedge-like structures have been investigated for a variety of soil conditions. The radar used for this study emitted short sinusoidal pulses of about 10-ns duration with an approximate center frequency of 150 MHz. Most of the ice wedges existed at depths of about 1 m in a variety of silty and sandy soils with both frozen and thawed active layers. The position of the wedges was usually identified from corresponding surface features. An artificial ice wedge in coarse-grained alluvium was also profiled as well as wedge-like structures of fine silt in a coarse-grained glacial outwash. All wedges and wedge-like structures produced a hyperbolic reflection profile except when an active layer of thawed, saturated silt was present which eliminated returns from the wedges. The peaks of the hyperbolas were sometimes masked by reflections from the permafrost table or other material interfaces, and multiple hyperbolas occurred at some sites. The dielectric constant of the host medium was often calculated from the linear portions of the hyperbolas and the results were verified by laboratory time domain reflectometry measurements performed on field samples. In some cases, hyperbolic profiles originated at several meters depth suggesting that deep ice wedges could be detected in areas of cold permafrost. |
author2 |
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH |
format |
Text |
author |
Arcone,Steven A Sellmann,Paul V Delaney,Allan J |
author_facet |
Arcone,Steven A Sellmann,Paul V Delaney,Allan J |
author_sort |
Arcone,Steven A |
title |
Radar Detection of Ice Wedges in Alaska |
title_short |
Radar Detection of Ice Wedges in Alaska |
title_full |
Radar Detection of Ice Wedges in Alaska |
title_fullStr |
Radar Detection of Ice Wedges in Alaska |
title_full_unstemmed |
Radar Detection of Ice Wedges in Alaska |
title_sort |
radar detection of ice wedges in alaska |
publishDate |
1982 |
url |
http://www.dtic.mil/docs/citations/ADA124571 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA124571 |
genre |
Ice permafrost wedge* Alaska |
genre_facet |
Ice permafrost wedge* Alaska |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA124571 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
_version_ |
1766027032866586624 |