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Titel |
Glacier topography and elevation changes derived from Pléiades sub-meter stereo images |
VerfasserIn |
E. Berthier, C. Vincent, E. Magnusson, Á. P. Gunnlaugsson, P. Pitte, E. Le Meur, M. Masiokas, L. Ruiz, F. Pálsson, J. M. C. Belart, P. Wagnon |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1994-0416
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Digitales Dokument |
URL |
Erschienen |
In: The Cryosphere ; 8, no. 6 ; Nr. 8, no. 6 (2014-12-10), S.2275-2291 |
Datensatznummer |
250116389
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Publikation (Nr.) |
copernicus.org/tc-8-2275-2014.pdf |
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Zusammenfassung |
In response to climate change, most glaciers are losing mass and hence
contribute to sea-level rise. Repeated and accurate mapping of their surface
topography is required to estimate their mass balance and to
extrapolate/calibrate sparse field glaciological measurements. In this study
we evaluate the potential of sub-meter stereo imagery from the recently
launched Pléiades satellites to derive digital elevation models (DEMs)
of glaciers and their elevation changes. Our five evaluation sites, where
nearly simultaneous field measurements were collected, are located in
Iceland, the European Alps, the central Andes, Nepal and Antarctica. For
Iceland, the Pléiades DEM is also compared to a lidar DEM. The vertical
biases of the Pléiades DEMs are less than 1 m if ground control points
(GCPs) are used, but reach up to 7 m without GCPs. Even without GCPs,
vertical biases can be reduced to a few decimetres by horizontal and
vertical co-registration of the DEMs to reference altimetric data on
ice-free terrain. Around these biases, the vertical precision of the
Pléiades DEMs is ±1 m and even ±0.5 m on the flat glacier
tongues (1σ confidence level). Similar precision levels are obtained in
the accumulation areas of glaciers and in Antarctica. We also demonstrate
the high potential of Pléiades DEMs for measuring seasonal, annual and
multi-annual elevation changes with an accuracy of 1 m or better if
cloud-free images are available. The negative region-wide mass balances of
glaciers in the Mont-Blanc area (−1.04 ± 0.23 m a−1 water
equivalent, w.e.) are revealed by differencing Satellite pour l'Observation de la Terre 5 (SPOT 5) and Pléiades DEMs
acquired in August 2003 and 2012, confirming the accelerated glacial wastage
in the European Alps. |
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