Toward improved sea ice freeboard observation with SAR altimetry using the physical retracker SAMOSA+
International audience Since 2010, the CryoSat-2 satellite mission has enabled to largely improve sea ice freeboard estimations. But due to the complexity of radar echoes over sea ice, freeboard retrieval from altimetry still presents some errors and biases that further limit the potential of these...
Published in: | Advances in Space Research |
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Main Authors: | , , , , , , , |
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Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2021
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Online Access: | https://insu.hal.science/insu-03671336 https://insu.hal.science/insu-03671336/document https://insu.hal.science/insu-03671336/file/1-s2.0-S0273117720300776-main.pdf https://doi.org/10.1016/j.asr.2020.02.001 |
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ftinsu:oai:HAL:insu-03671336v1 |
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openpolar |
institution |
Open Polar |
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Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
Sea ice freeboard Remote sensing Arctic Delay-Doppler Altimetry SAMOSA+ TFMRA Hamming Zero-padding [SDU]Sciences of the Universe [physics] |
spellingShingle |
Sea ice freeboard Remote sensing Arctic Delay-Doppler Altimetry SAMOSA+ TFMRA Hamming Zero-padding [SDU]Sciences of the Universe [physics] Laforge, Antoine Fleury, Sara Dinardo, Salvatore Garnier, Florent Remy, Frédérique Benveniste, Jérôme Bouffard, Jérôme Verley, Jonas Toward improved sea ice freeboard observation with SAR altimetry using the physical retracker SAMOSA+ |
topic_facet |
Sea ice freeboard Remote sensing Arctic Delay-Doppler Altimetry SAMOSA+ TFMRA Hamming Zero-padding [SDU]Sciences of the Universe [physics] |
description |
International audience Since 2010, the CryoSat-2 satellite mission has enabled to largely improve sea ice freeboard estimations. But due to the complexity of radar echoes over sea ice, freeboard retrieval from altimetry still presents some errors and biases that further limit the potential of these observations for climate studies or for assimilation into models. Various methods have been explored, producing a large range of freeboard estimations. In this study, we analyze the main steps of the radar freeboard computation developed as part of the Cryo-SeaNice Project. The objective is to quantify the impacts of each processing method and to identify optimal strategies to improve freeboard estimations from SAR altimetry measurements. We consider two SAR processing options: the Hamming Window (HW) and with the Zero-Padding (ZP), and 2 retrackers: the Threshold First Maximum Retracker Algorithm (TFMRA) based on heuristic measurements and SAMOSA+ a retracker declined from model based analysis of the surface back-scatter. Four freeboard solutions are generated from combinations of the 2 processing options (HW and ZP or ZP only) and the 2 types of retrackers. In addition, an alternative to the Hamming Window method to filter out side-lobes errors is presented. The impacts of the different approaches to estimate freeboard are quantified from comparisons with Operation Ice Bridge (OIB) and the Beaufort Gyre Exploration project (BGEP) in situ data. Our results show that SAMOSA+ provides more precise freeboard estimations. This new time-series is available on CTOH website. We also identified some impacts of the Hamming Window for both retrackers. Finally, we present the potential of using the simpler threshold retracker but with a correction to account for the surface roughness that is calibrated against SAMOSA+. |
author2 |
Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Laforge, Antoine Fleury, Sara Dinardo, Salvatore Garnier, Florent Remy, Frédérique Benveniste, Jérôme Bouffard, Jérôme Verley, Jonas |
author_facet |
Laforge, Antoine Fleury, Sara Dinardo, Salvatore Garnier, Florent Remy, Frédérique Benveniste, Jérôme Bouffard, Jérôme Verley, Jonas |
author_sort |
Laforge, Antoine |
title |
Toward improved sea ice freeboard observation with SAR altimetry using the physical retracker SAMOSA+ |
title_short |
Toward improved sea ice freeboard observation with SAR altimetry using the physical retracker SAMOSA+ |
title_full |
Toward improved sea ice freeboard observation with SAR altimetry using the physical retracker SAMOSA+ |
title_fullStr |
Toward improved sea ice freeboard observation with SAR altimetry using the physical retracker SAMOSA+ |
title_full_unstemmed |
Toward improved sea ice freeboard observation with SAR altimetry using the physical retracker SAMOSA+ |
title_sort |
toward improved sea ice freeboard observation with sar altimetry using the physical retracker samosa+ |
publisher |
HAL CCSD |
publishDate |
2021 |
url |
https://insu.hal.science/insu-03671336 https://insu.hal.science/insu-03671336/document https://insu.hal.science/insu-03671336/file/1-s2.0-S0273117720300776-main.pdf https://doi.org/10.1016/j.asr.2020.02.001 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Sea ice |
genre_facet |
Arctic Sea ice |
op_source |
Advances in Space Research https://insu.hal.science/insu-03671336 Advances in Space Research, 2021, 68, pp.732-745. ⟨10.1016/j.asr.2020.02.001⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.asr.2020.02.001 insu-03671336 https://insu.hal.science/insu-03671336 https://insu.hal.science/insu-03671336/document https://insu.hal.science/insu-03671336/file/1-s2.0-S0273117720300776-main.pdf BIBCODE: 2021AdSpR.68.732L doi:10.1016/j.asr.2020.02.001 |
op_rights |
http://creativecommons.org/licenses/by-nc-nd/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1016/j.asr.2020.02.001 |
container_title |
Advances in Space Research |
container_volume |
68 |
container_issue |
2 |
container_start_page |
732 |
op_container_end_page |
745 |
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1796305965467828224 |
spelling |
ftinsu:oai:HAL:insu-03671336v1 2024-04-14T08:08:32+00:00 Toward improved sea ice freeboard observation with SAR altimetry using the physical retracker SAMOSA+ Laforge, Antoine Fleury, Sara Dinardo, Salvatore Garnier, Florent Remy, Frédérique Benveniste, Jérôme Bouffard, Jérôme Verley, Jonas Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) 2021 https://insu.hal.science/insu-03671336 https://insu.hal.science/insu-03671336/document https://insu.hal.science/insu-03671336/file/1-s2.0-S0273117720300776-main.pdf https://doi.org/10.1016/j.asr.2020.02.001 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.1016/j.asr.2020.02.001 insu-03671336 https://insu.hal.science/insu-03671336 https://insu.hal.science/insu-03671336/document https://insu.hal.science/insu-03671336/file/1-s2.0-S0273117720300776-main.pdf BIBCODE: 2021AdSpR.68.732L doi:10.1016/j.asr.2020.02.001 http://creativecommons.org/licenses/by-nc-nd/ info:eu-repo/semantics/OpenAccess Advances in Space Research https://insu.hal.science/insu-03671336 Advances in Space Research, 2021, 68, pp.732-745. ⟨10.1016/j.asr.2020.02.001⟩ Sea ice freeboard Remote sensing Arctic Delay-Doppler Altimetry SAMOSA+ TFMRA Hamming Zero-padding [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2021 ftinsu https://doi.org/10.1016/j.asr.2020.02.001 2024-03-21T17:13:45Z International audience Since 2010, the CryoSat-2 satellite mission has enabled to largely improve sea ice freeboard estimations. But due to the complexity of radar echoes over sea ice, freeboard retrieval from altimetry still presents some errors and biases that further limit the potential of these observations for climate studies or for assimilation into models. Various methods have been explored, producing a large range of freeboard estimations. In this study, we analyze the main steps of the radar freeboard computation developed as part of the Cryo-SeaNice Project. The objective is to quantify the impacts of each processing method and to identify optimal strategies to improve freeboard estimations from SAR altimetry measurements. We consider two SAR processing options: the Hamming Window (HW) and with the Zero-Padding (ZP), and 2 retrackers: the Threshold First Maximum Retracker Algorithm (TFMRA) based on heuristic measurements and SAMOSA+ a retracker declined from model based analysis of the surface back-scatter. Four freeboard solutions are generated from combinations of the 2 processing options (HW and ZP or ZP only) and the 2 types of retrackers. In addition, an alternative to the Hamming Window method to filter out side-lobes errors is presented. The impacts of the different approaches to estimate freeboard are quantified from comparisons with Operation Ice Bridge (OIB) and the Beaufort Gyre Exploration project (BGEP) in situ data. Our results show that SAMOSA+ provides more precise freeboard estimations. This new time-series is available on CTOH website. We also identified some impacts of the Hamming Window for both retrackers. Finally, we present the potential of using the simpler threshold retracker but with a correction to account for the surface roughness that is calibrated against SAMOSA+. Article in Journal/Newspaper Arctic Sea ice Institut national des sciences de l'Univers: HAL-INSU Arctic Advances in Space Research 68 2 732 745 |