Ensemble matching of repeat satellite images applied to measure fast-changing ice flow, verified with mountain climber trajectories on Khumbu icefall, Mount Everest
Velocities within an icefall are typically the fastest within a glacier system and experience complex flow. The combination of convergent and fast flow, and steep slope generate a quickly changing and intensely fractured surface. This complicates velocity extraction from repeat satellite images, esp...
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ftdoajarticles:oai:doaj.org/article:173fc548746e49d4b9808d285594c747 2023-05-15T16:57:35+02:00 Ensemble matching of repeat satellite images applied to measure fast-changing ice flow, verified with mountain climber trajectories on Khumbu icefall, Mount Everest Bas Altena Andreas Kääb 2020-12-01T00:00:00Z https://doi.org/10.1017/jog.2020.66 https://doaj.org/article/173fc548746e49d4b9808d285594c747 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0022143020000660/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2020.66 0022-1430 1727-5652 https://doaj.org/article/173fc548746e49d4b9808d285594c747 Journal of Glaciology, Vol 66, Pp 905-915 (2020) Glacier flow ice velocity remote sensing Environmental sciences GE1-350 Meteorology. Climatology QC851-999 article 2020 ftdoajarticles https://doi.org/10.1017/jog.2020.66 2023-03-12T01:30:57Z Velocities within an icefall are typically the fastest within a glacier system and experience complex flow. The combination of convergent and fast flow, and steep slope generate a quickly changing and intensely fractured surface. This complicates velocity extraction from repeat satellite images, especially when common pattern matching procedures are used. In this study, we exploit the high temporal revisit of medium-resolution satellite images using a novel image matching technique, ensemble matching, making it possible to generate a high-resolution (30 m) velocity field from high-repeat image sequences despite challenging image conditions. We demonstrate this technique for the first time in the glaciology domain using repeat Sentinel-2 optical data over the famous Khumbu icefall, situated on the southern slopes of Mount Everest. Estimates of velocity go just over 1 m d−1, which is slower than summer velocities from noisy single pair image matching. This icefall is frequently crossed by high-altitude mountaineers who use a route confined by fixed ropes and ladders set out every season. The mountain climbers typically record their trajectory on their personal satellite navigation device. We use such volunteered geographic information to verify our velocity estimates, confirming our underestimation with ensemble matching. Besides unprecedented remotely sensed surface velocities over the icefall, we also note that the generated velocity field can aid with the planning of a safe passage through this icefall. Article in Journal/Newspaper Journal of Glaciology Directory of Open Access Journals: DOAJ Articles Journal of Glaciology 66 260 905 915 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Glacier flow ice velocity remote sensing Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
spellingShingle |
Glacier flow ice velocity remote sensing Environmental sciences GE1-350 Meteorology. Climatology QC851-999 Bas Altena Andreas Kääb Ensemble matching of repeat satellite images applied to measure fast-changing ice flow, verified with mountain climber trajectories on Khumbu icefall, Mount Everest |
topic_facet |
Glacier flow ice velocity remote sensing Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
description |
Velocities within an icefall are typically the fastest within a glacier system and experience complex flow. The combination of convergent and fast flow, and steep slope generate a quickly changing and intensely fractured surface. This complicates velocity extraction from repeat satellite images, especially when common pattern matching procedures are used. In this study, we exploit the high temporal revisit of medium-resolution satellite images using a novel image matching technique, ensemble matching, making it possible to generate a high-resolution (30 m) velocity field from high-repeat image sequences despite challenging image conditions. We demonstrate this technique for the first time in the glaciology domain using repeat Sentinel-2 optical data over the famous Khumbu icefall, situated on the southern slopes of Mount Everest. Estimates of velocity go just over 1 m d−1, which is slower than summer velocities from noisy single pair image matching. This icefall is frequently crossed by high-altitude mountaineers who use a route confined by fixed ropes and ladders set out every season. The mountain climbers typically record their trajectory on their personal satellite navigation device. We use such volunteered geographic information to verify our velocity estimates, confirming our underestimation with ensemble matching. Besides unprecedented remotely sensed surface velocities over the icefall, we also note that the generated velocity field can aid with the planning of a safe passage through this icefall. |
format |
Article in Journal/Newspaper |
author |
Bas Altena Andreas Kääb |
author_facet |
Bas Altena Andreas Kääb |
author_sort |
Bas Altena |
title |
Ensemble matching of repeat satellite images applied to measure fast-changing ice flow, verified with mountain climber trajectories on Khumbu icefall, Mount Everest |
title_short |
Ensemble matching of repeat satellite images applied to measure fast-changing ice flow, verified with mountain climber trajectories on Khumbu icefall, Mount Everest |
title_full |
Ensemble matching of repeat satellite images applied to measure fast-changing ice flow, verified with mountain climber trajectories on Khumbu icefall, Mount Everest |
title_fullStr |
Ensemble matching of repeat satellite images applied to measure fast-changing ice flow, verified with mountain climber trajectories on Khumbu icefall, Mount Everest |
title_full_unstemmed |
Ensemble matching of repeat satellite images applied to measure fast-changing ice flow, verified with mountain climber trajectories on Khumbu icefall, Mount Everest |
title_sort |
ensemble matching of repeat satellite images applied to measure fast-changing ice flow, verified with mountain climber trajectories on khumbu icefall, mount everest |
publisher |
Cambridge University Press |
publishDate |
2020 |
url |
https://doi.org/10.1017/jog.2020.66 https://doaj.org/article/173fc548746e49d4b9808d285594c747 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology, Vol 66, Pp 905-915 (2020) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0022143020000660/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2020.66 0022-1430 1727-5652 https://doaj.org/article/173fc548746e49d4b9808d285594c747 |
op_doi |
https://doi.org/10.1017/jog.2020.66 |
container_title |
Journal of Glaciology |
container_volume |
66 |
container_issue |
260 |
container_start_page |
905 |
op_container_end_page |
915 |
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1766049147986640896 |