Variation in Visual and Near-Infrared Contrast with a Snow Background.
Visual and near-infrared concealment against a snow cover are considered in terms of the daily and longer-term variation in albedo of a shallow (< or = 26 cm) snow cover. Examples of albedo of a Vermont snow cover demonstrate the influence of time of day (solar angle), incident solar radiation, s...
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ftdtic:ADA289710 2023-05-15T16:37:47+02:00 Variation in Visual and Near-Infrared Contrast with a Snow Background. Peck, Lindamae COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH 1994-08 text/html http://www.dtic.mil/docs/citations/ADA289710 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA289710 en eng http://www.dtic.mil/docs/citations/ADA289710 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Optics Snow Ice and Permafrost *SNOW COVER *NEAR INFRARED RADIATION *ALBEDO INFRARED DETECTION CONTRAST ILLUMINATION REFLECTION CONSISTENCY SOILS SEASONAL VARIATIONS INFRARED IMAGES BACKGROUND VISUAL PERCEPTION SOLAR RADIATION MOISTURE SURFACE TEMPERATURE DAILY OCCURRENCE DIURNAL VARIATIONS VISUAL TARGETS CONCEALMENT SUN WHITE(COLOR) SPN-19950112044 Text 1994 ftdtic 2016-02-19T11:55:40Z Visual and near-infrared concealment against a snow cover are considered in terms of the daily and longer-term variation in albedo of a shallow (< or = 26 cm) snow cover. Examples of albedo of a Vermont snow cover demonstrate the influence of time of day (solar angle), incident solar radiation, snow depth, and snow wetness. Most albedos felt within the range 0.75-0.98. The most consistent variation was a decrease in albedo during the morning as the sun angle increased and a corresponding increase with decreasing sun angle in the afternoon. Albedo was low when the snow surface temperature indicated melting was occurring or when an increase in temperature of the soil beneath the snow cover indicated solar radiation was being absorbed by the soil. Examples of the diurnal variation in sun angle and the seasonal variation in maximum potential solar radiation, as calculated from site latitude and longitude and calendar date, are presented. (AN) Text Ice permafrost Defense Technical Information Center: DTIC Technical Reports database |
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Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Optics Snow Ice and Permafrost *SNOW COVER *NEAR INFRARED RADIATION *ALBEDO INFRARED DETECTION CONTRAST ILLUMINATION REFLECTION CONSISTENCY SOILS SEASONAL VARIATIONS INFRARED IMAGES BACKGROUND VISUAL PERCEPTION SOLAR RADIATION MOISTURE SURFACE TEMPERATURE DAILY OCCURRENCE DIURNAL VARIATIONS VISUAL TARGETS CONCEALMENT SUN WHITE(COLOR) SPN-19950112044 |
spellingShingle |
Optics Snow Ice and Permafrost *SNOW COVER *NEAR INFRARED RADIATION *ALBEDO INFRARED DETECTION CONTRAST ILLUMINATION REFLECTION CONSISTENCY SOILS SEASONAL VARIATIONS INFRARED IMAGES BACKGROUND VISUAL PERCEPTION SOLAR RADIATION MOISTURE SURFACE TEMPERATURE DAILY OCCURRENCE DIURNAL VARIATIONS VISUAL TARGETS CONCEALMENT SUN WHITE(COLOR) SPN-19950112044 Peck, Lindamae Variation in Visual and Near-Infrared Contrast with a Snow Background. |
topic_facet |
Optics Snow Ice and Permafrost *SNOW COVER *NEAR INFRARED RADIATION *ALBEDO INFRARED DETECTION CONTRAST ILLUMINATION REFLECTION CONSISTENCY SOILS SEASONAL VARIATIONS INFRARED IMAGES BACKGROUND VISUAL PERCEPTION SOLAR RADIATION MOISTURE SURFACE TEMPERATURE DAILY OCCURRENCE DIURNAL VARIATIONS VISUAL TARGETS CONCEALMENT SUN WHITE(COLOR) SPN-19950112044 |
description |
Visual and near-infrared concealment against a snow cover are considered in terms of the daily and longer-term variation in albedo of a shallow (< or = 26 cm) snow cover. Examples of albedo of a Vermont snow cover demonstrate the influence of time of day (solar angle), incident solar radiation, snow depth, and snow wetness. Most albedos felt within the range 0.75-0.98. The most consistent variation was a decrease in albedo during the morning as the sun angle increased and a corresponding increase with decreasing sun angle in the afternoon. Albedo was low when the snow surface temperature indicated melting was occurring or when an increase in temperature of the soil beneath the snow cover indicated solar radiation was being absorbed by the soil. Examples of the diurnal variation in sun angle and the seasonal variation in maximum potential solar radiation, as calculated from site latitude and longitude and calendar date, are presented. (AN) |
author2 |
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH |
format |
Text |
author |
Peck, Lindamae |
author_facet |
Peck, Lindamae |
author_sort |
Peck, Lindamae |
title |
Variation in Visual and Near-Infrared Contrast with a Snow Background. |
title_short |
Variation in Visual and Near-Infrared Contrast with a Snow Background. |
title_full |
Variation in Visual and Near-Infrared Contrast with a Snow Background. |
title_fullStr |
Variation in Visual and Near-Infrared Contrast with a Snow Background. |
title_full_unstemmed |
Variation in Visual and Near-Infrared Contrast with a Snow Background. |
title_sort |
variation in visual and near-infrared contrast with a snow background. |
publishDate |
1994 |
url |
http://www.dtic.mil/docs/citations/ADA289710 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA289710 |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA289710 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
_version_ |
1766028088256233472 |