Coherent backscatter enhancement in bistatic Ku- and X-band radar observations of dry snow
The coherent backscatter opposition effect (CBOE) enhances the backscatter intensity of electromagnetic waves by up to a factor of 2 in a very narrow cone around the direct return direction when multiple scattering occurs in a weakly absorbing, disordered medium. So far, this effect has not been inv...
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2022
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00061915 2023-05-15T18:32:33+02:00 Coherent backscatter enhancement in bistatic Ku- and X-band radar observations of dry snow Stefko, Marcel Leinss, Silvan Frey, Othmar Hajnsek, Irena 2022-07 electronic https://doi.org/10.5194/tc-16-2859-2022 https://noa.gwlb.de/receive/cop_mods_00061915 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00061282/tc-16-2859-2022.pdf https://tc.copernicus.org/articles/16/2859/2022/tc-16-2859-2022.pdf eng eng Copernicus Publications The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-16-2859-2022 https://noa.gwlb.de/receive/cop_mods_00061915 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00061282/tc-16-2859-2022.pdf https://tc.copernicus.org/articles/16/2859/2022/tc-16-2859-2022.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2022 ftnonlinearchiv https://doi.org/10.5194/tc-16-2859-2022 2022-07-31T23:11:44Z The coherent backscatter opposition effect (CBOE) enhances the backscatter intensity of electromagnetic waves by up to a factor of 2 in a very narrow cone around the direct return direction when multiple scattering occurs in a weakly absorbing, disordered medium. So far, this effect has not been investigated in terrestrial snow in the microwave spectrum. It has also received little attention in scattering models. We present the first characterization of the CBOE in dry snow using ground-based and spaceborne bistatic radar systems. For a seasonal snowpack in the Ku-band (17.2 GHz), we found backscatter enhancement of 50 %–60 % (+1.8–2.0 dB) at a zero bistatic angle and a peak half-width at half-maximum (HWHM) of 0.25∘. In the X-band (9.65 GHz), we found backscatter enhancement of at least 35 % (+1.3 dB) and an estimated HWHM of 0.12∘ in the accumulation areas of glaciers in the Jungfrau–Aletsch region, Switzerland. Sampling of the peak shape at different bistatic angles allows estimating the scattering and absorption mean free paths, ΛT and ΛA. In the VV polarization, we obtained ΛT=0.4±0.1 m and ΛA=19±12 m at the Ku-band and ΛT=2.1±0.4 m and ΛA=21.8±2.7 m at the X-band, assuming an optically thick medium. The HH polarization yielded similar results. The observed backscatter enhancement is thus significant enough to require consideration in backscatter models describing monostatic and bistatic radar experiments. Enhanced backscattering beyond the Earth, on the surface of solar system bodies, has been interpreted as being caused by the presence of water ice. In agreement with this interpretation, our results confirm the presence of the CBOE at X- and Ku-band frequencies in terrestrial snow. Article in Journal/Newspaper The Cryosphere Niedersächsisches Online-Archiv NOA The Cryosphere 16 7 2859 2879 |
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article Verlagsveröffentlichung Stefko, Marcel Leinss, Silvan Frey, Othmar Hajnsek, Irena Coherent backscatter enhancement in bistatic Ku- and X-band radar observations of dry snow |
topic_facet |
article Verlagsveröffentlichung |
description |
The coherent backscatter opposition effect (CBOE) enhances the backscatter intensity of electromagnetic waves by up to a factor of 2 in a very narrow cone around the direct return direction when multiple scattering occurs in a weakly absorbing, disordered medium. So far, this effect has not been investigated in terrestrial snow in the microwave spectrum. It has also received little attention in scattering models. We present the first characterization of the CBOE in dry snow using ground-based and spaceborne bistatic radar systems. For a seasonal snowpack in the Ku-band (17.2 GHz), we found backscatter enhancement of 50 %–60 % (+1.8–2.0 dB) at a zero bistatic angle and a peak half-width at half-maximum (HWHM) of 0.25∘. In the X-band (9.65 GHz), we found backscatter enhancement of at least 35 % (+1.3 dB) and an estimated HWHM of 0.12∘ in the accumulation areas of glaciers in the Jungfrau–Aletsch region, Switzerland. Sampling of the peak shape at different bistatic angles allows estimating the scattering and absorption mean free paths, ΛT and ΛA. In the VV polarization, we obtained ΛT=0.4±0.1 m and ΛA=19±12 m at the Ku-band and ΛT=2.1±0.4 m and ΛA=21.8±2.7 m at the X-band, assuming an optically thick medium. The HH polarization yielded similar results. The observed backscatter enhancement is thus significant enough to require consideration in backscatter models describing monostatic and bistatic radar experiments. Enhanced backscattering beyond the Earth, on the surface of solar system bodies, has been interpreted as being caused by the presence of water ice. In agreement with this interpretation, our results confirm the presence of the CBOE at X- and Ku-band frequencies in terrestrial snow. |
format |
Article in Journal/Newspaper |
author |
Stefko, Marcel Leinss, Silvan Frey, Othmar Hajnsek, Irena |
author_facet |
Stefko, Marcel Leinss, Silvan Frey, Othmar Hajnsek, Irena |
author_sort |
Stefko, Marcel |
title |
Coherent backscatter enhancement in bistatic Ku- and X-band radar observations of dry snow |
title_short |
Coherent backscatter enhancement in bistatic Ku- and X-band radar observations of dry snow |
title_full |
Coherent backscatter enhancement in bistatic Ku- and X-band radar observations of dry snow |
title_fullStr |
Coherent backscatter enhancement in bistatic Ku- and X-band radar observations of dry snow |
title_full_unstemmed |
Coherent backscatter enhancement in bistatic Ku- and X-band radar observations of dry snow |
title_sort |
coherent backscatter enhancement in bistatic ku- and x-band radar observations of dry snow |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-2859-2022 https://noa.gwlb.de/receive/cop_mods_00061915 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00061282/tc-16-2859-2022.pdf https://tc.copernicus.org/articles/16/2859/2022/tc-16-2859-2022.pdf |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_relation |
The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-16-2859-2022 https://noa.gwlb.de/receive/cop_mods_00061915 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00061282/tc-16-2859-2022.pdf https://tc.copernicus.org/articles/16/2859/2022/tc-16-2859-2022.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/tc-16-2859-2022 |
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The Cryosphere |
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16 |
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7 |
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2859 |
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2879 |
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