SAR-INTERFEROMETRIC FLOW VELOCITIES OF TWO TIDEWATER GLACIERS IN NW SPITSBERGEN: METHODS AND RESULTS
This paper presents the results of flow velocity studies of two large tidewater glaciers in Svalbard, Aavatsmarkbreen and Comfortlessbreen. This study is part of the international GECALVEX project and interferometric analysis have been performed thanks to ESA project CP1-1076. During the field campa...
| Main Authors: | , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.212.3816 http://earth.esa.int/workshops/fringe03/proceedings/papers/118_Perski.pdf |
| Summary: | This paper presents the results of flow velocity studies of two large tidewater glaciers in Svalbard, Aavatsmarkbreen and Comfortlessbreen. This study is part of the international GECALVEX project and interferometric analysis have been performed thanks to ESA project CP1-1076. During the field campaigns of July 2000 and April 2001 the GPS data of flow velocities and elevation have been registered, using static and kinematic methods. Also the flow velocity for the glaciers have been calculated from SAR interferometric satellite measurements using both ascending and descending satellite passes. To calculate flow velocity field from ascending and descending observations, a precise topographic information was required. As input data, the glacier slope and flow direction (this only in a case of calculations with single pass) must be known to a high level of accuracy. To prepare such data and to reduce the effect of topography on the interferogram the 20-m DEM provided by Cartographic Branch of the Norwegian Polar Institute (NP) have been applied. Additional problem have been identified in as much as the DEM presents very detailed and accurate height information for the ground but its accuracy for the glacier surfaces leaves much to be desired. Elevation data for glaciers was collected mostly in 1936 from photogrammetric surveys. Additionally, owning the interpolation errors of up to 50 m in respect of the sparse data elevation points, the quality of DEM on glaciers has been degraded. To try to avoid this problem, the NP DEM have been updated for Aavatsmarkbreen and Comfortlessbreen areas using |
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