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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Copernicus Publications
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Online Access: | https://doi.org/10.5194/tc-16-2859-2022 https://tc.copernicus.org/articles/16/2859/2022/tc-16-2859-2022.pdf https://doaj.org/article/805bd9f821f04ae994283af7f8d99f85 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:805bd9f821f04ae994283af7f8d99f85 2023-05-15T18:32:16+02:00 Coherent backscatter enhancement in bistatic Ku- and X-band radar observations of dry snow M. Stefko S. Leinss O. Frey I. Hajnsek 2022-07-01 https://doi.org/10.5194/tc-16-2859-2022 https://tc.copernicus.org/articles/16/2859/2022/tc-16-2859-2022.pdf https://doaj.org/article/805bd9f821f04ae994283af7f8d99f85 en eng Copernicus Publications doi:10.5194/tc-16-2859-2022 1994-0416 1994-0424 https://tc.copernicus.org/articles/16/2859/2022/tc-16-2859-2022.pdf https://doaj.org/article/805bd9f821f04ae994283af7f8d99f85 undefined The Cryosphere, Vol 16, Pp 2859-2879 (2022) info geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2022 fttriple https://doi.org/10.5194/tc-16-2859-2022 2023-01-22T18:19:20Z 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 Unknown The Cryosphere 16 7 2859 2879 |
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English |
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info geo M. Stefko S. Leinss O. Frey I. Hajnsek Coherent backscatter enhancement in bistatic Ku- and X-band radar observations of dry snow |
topic_facet |
info geo |
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 |
M. Stefko S. Leinss O. Frey I. Hajnsek |
author_facet |
M. Stefko S. Leinss O. Frey I. Hajnsek |
author_sort |
M. Stefko |
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://tc.copernicus.org/articles/16/2859/2022/tc-16-2859-2022.pdf https://doaj.org/article/805bd9f821f04ae994283af7f8d99f85 |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 16, Pp 2859-2879 (2022) |
op_relation |
doi:10.5194/tc-16-2859-2022 1994-0416 1994-0424 https://tc.copernicus.org/articles/16/2859/2022/tc-16-2859-2022.pdf https://doaj.org/article/805bd9f821f04ae994283af7f8d99f85 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-16-2859-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
7 |
container_start_page |
2859 |
op_container_end_page |
2879 |
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