Empirical correction of systematic orthorectification error in Sentinel-2 velocity fields for Greenlandic outlet glaciers
By utilising imagery from overlapping orbits, the Sentinel-2 programme offers high-frequency observations of high-latitude environments well in excess of its 5 d repeat rate, which is valuable for obtaining large-scale records of rapid environmental change. However, the production of glacier velocit...
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Copernicus Publications
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Online Access: | https://doi.org/10.5194/tc-16-2629-2022 https://tc.copernicus.org/articles/16/2629/2022/tc-16-2629-2022.pdf https://doaj.org/article/cf589129f62e4c80914d49bf1bc934b3 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:cf589129f62e4c80914d49bf1bc934b3 2023-05-15T16:21:17+02:00 Empirical correction of systematic orthorectification error in Sentinel-2 velocity fields for Greenlandic outlet glaciers T. R. Chudley I. M. Howat B. Yadav M.-J. Noh 2022-07-01 https://doi.org/10.5194/tc-16-2629-2022 https://tc.copernicus.org/articles/16/2629/2022/tc-16-2629-2022.pdf https://doaj.org/article/cf589129f62e4c80914d49bf1bc934b3 en eng Copernicus Publications doi:10.5194/tc-16-2629-2022 1994-0416 1994-0424 https://tc.copernicus.org/articles/16/2629/2022/tc-16-2629-2022.pdf https://doaj.org/article/cf589129f62e4c80914d49bf1bc934b3 undefined The Cryosphere, Vol 16, Pp 2629-2642 (2022) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2022 fttriple https://doi.org/10.5194/tc-16-2629-2022 2023-01-22T17:46:45Z By utilising imagery from overlapping orbits, the Sentinel-2 programme offers high-frequency observations of high-latitude environments well in excess of its 5 d repeat rate, which is valuable for obtaining large-scale records of rapid environmental change. However, the production of glacier velocity datasets from optical feature tracking of Sentinel-2 imagery is limited by the orthorectification error in ESA products, which introduces significant systematic errors (on the order of tens of metres) into displacement fields produced from cross-track image pairs. As a result, most standard processing chains ignore cross-track pairs, which limits the opportunity to fully benefit from Sentinel-2's high-frequency observations during periods of intermittent coverage or for rapid dynamic events. Here, we use temporally complete glacier velocity datasets to empirically reconstruct systematic error, allowing for the corrected velocity datasets to be produced for four key fast-flowing marine-terminating outlets across the Greenland Ice Sheet between 2017–2021. We show that corrected data agree well with comparison velocity datasets derived from optical (Landsat 8) and synthetic aperture radar (Sentinel-1) data. The density of available velocity pairs produces a noisier dataset than for these comparative records, but a best-fit velocity reconstructed by time-series modelling can identify periods of rapid change (e.g. summer slowdowns), even where gaps exist in other datasets. We use the empirical error maps to identify that the commercial DEM used to orthorectify Sentinel-2 scenes over Greenland between 2017–2021 likely shares data sources with freely available public DEMs, opening avenues for the analytical correction of Sentinel-2 glacier velocity fields in the future. Article in Journal/Newspaper glacier Greenland greenlandic Ice Sheet The Cryosphere Unknown Greenland The Sentinel ENVELOPE(73.317,73.317,-52.983,-52.983) The Cryosphere 16 6 2629 2642 |
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fttriple |
language |
English |
topic |
geo envir |
spellingShingle |
geo envir T. R. Chudley I. M. Howat B. Yadav M.-J. Noh Empirical correction of systematic orthorectification error in Sentinel-2 velocity fields for Greenlandic outlet glaciers |
topic_facet |
geo envir |
description |
By utilising imagery from overlapping orbits, the Sentinel-2 programme offers high-frequency observations of high-latitude environments well in excess of its 5 d repeat rate, which is valuable for obtaining large-scale records of rapid environmental change. However, the production of glacier velocity datasets from optical feature tracking of Sentinel-2 imagery is limited by the orthorectification error in ESA products, which introduces significant systematic errors (on the order of tens of metres) into displacement fields produced from cross-track image pairs. As a result, most standard processing chains ignore cross-track pairs, which limits the opportunity to fully benefit from Sentinel-2's high-frequency observations during periods of intermittent coverage or for rapid dynamic events. Here, we use temporally complete glacier velocity datasets to empirically reconstruct systematic error, allowing for the corrected velocity datasets to be produced for four key fast-flowing marine-terminating outlets across the Greenland Ice Sheet between 2017–2021. We show that corrected data agree well with comparison velocity datasets derived from optical (Landsat 8) and synthetic aperture radar (Sentinel-1) data. The density of available velocity pairs produces a noisier dataset than for these comparative records, but a best-fit velocity reconstructed by time-series modelling can identify periods of rapid change (e.g. summer slowdowns), even where gaps exist in other datasets. We use the empirical error maps to identify that the commercial DEM used to orthorectify Sentinel-2 scenes over Greenland between 2017–2021 likely shares data sources with freely available public DEMs, opening avenues for the analytical correction of Sentinel-2 glacier velocity fields in the future. |
format |
Article in Journal/Newspaper |
author |
T. R. Chudley I. M. Howat B. Yadav M.-J. Noh |
author_facet |
T. R. Chudley I. M. Howat B. Yadav M.-J. Noh |
author_sort |
T. R. Chudley |
title |
Empirical correction of systematic orthorectification error in Sentinel-2 velocity fields for Greenlandic outlet glaciers |
title_short |
Empirical correction of systematic orthorectification error in Sentinel-2 velocity fields for Greenlandic outlet glaciers |
title_full |
Empirical correction of systematic orthorectification error in Sentinel-2 velocity fields for Greenlandic outlet glaciers |
title_fullStr |
Empirical correction of systematic orthorectification error in Sentinel-2 velocity fields for Greenlandic outlet glaciers |
title_full_unstemmed |
Empirical correction of systematic orthorectification error in Sentinel-2 velocity fields for Greenlandic outlet glaciers |
title_sort |
empirical correction of systematic orthorectification error in sentinel-2 velocity fields for greenlandic outlet glaciers |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-2629-2022 https://tc.copernicus.org/articles/16/2629/2022/tc-16-2629-2022.pdf https://doaj.org/article/cf589129f62e4c80914d49bf1bc934b3 |
long_lat |
ENVELOPE(73.317,73.317,-52.983,-52.983) |
geographic |
Greenland The Sentinel |
geographic_facet |
Greenland The Sentinel |
genre |
glacier Greenland greenlandic Ice Sheet The Cryosphere |
genre_facet |
glacier Greenland greenlandic Ice Sheet The Cryosphere |
op_source |
The Cryosphere, Vol 16, Pp 2629-2642 (2022) |
op_relation |
doi:10.5194/tc-16-2629-2022 1994-0416 1994-0424 https://tc.copernicus.org/articles/16/2629/2022/tc-16-2629-2022.pdf https://doaj.org/article/cf589129f62e4c80914d49bf1bc934b3 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-16-2629-2022 |
container_title |
The Cryosphere |
container_volume |
16 |
container_issue |
6 |
container_start_page |
2629 |
op_container_end_page |
2642 |
_version_ |
1766009290580033536 |