Racoviteanu A. E. auteur aut IRD Manley W. F. auteur aut IRD Arnaud Yves auteur aut IRD Williams M. W. auteur aut IRD text journalArticle eng text/pdf born digital access This paper evaluates the suitability of readily available elevation data derived from recent sensors - the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and the Shuttle Radar Topography Mission (SRTM) - for glaciological applications. The study area is Nevado Coropuna (6426 m), situated in Cordillera Ampato of Southern Peru. The glaciated area was 82.6 km(2) in 1962, based on aerial photography. We estimate the glacier area to be ca. 60.8 km(2) in 2000, based on analysis of the ASTER LIB scene. We used two 1:50,000 topographic maps constructed from 1955 aerial photography to create a digital elevation model with 30 in resolution, which we used as a reference dataset. Of the various interpolation techniques examined, the TOPOGRID algorithm was found to be superior to other techniques, and yielded a DEM with a vertical accuracy of +/- 14.7 m. The 1955 DEM was compared to the SRTM DEM (2000) and ASTER DEM (2001) on a cell-by-cell basis. Steps included: validating the DEM's against field GPS survey points on rock areas; visualization techniques such as shaded relief and contour maps; quantifying errors (bias) in each DEM; correlating vertical differences between various DEM's with topographic characteristics (elevation, slope and aspect) and subtracting DEM elevations on a cell-by-cell basis. The RMS error of the SRTM DEM with respect to GPS points on non-glaciated areas was 23 m. The ASTER DEM had a RMS error of 61 m with respect to GPS points and displayed 200-300 m horizontal offsets and elevation 'spikes' on the glaciated area when compared to the DEM from topographic data. Cell-by-cell comparison of SRTM and ASTER-derived elevations with topographic data showed ablation at the toes of the glaciers (-25 m to -75 m surface lowering) and an apparent thickening at the summits. The mean altitude difference on glaciated area (SRTM minus topographic DEM) was - 5 m, pointing towards a lowering of the glacier surface during the period 1955-2000. Spurious values on the glacier surface in the ASTER DEM affected the analysis and thus prevented us from quantifying the glacier changes based on the ASTER data. specialized digital elevation model DEM geographic information systems GIS Andes glaciology DEM generation ASTER SRTM 062 122 59 1-4 110-125 2007 0921-8181 https://www.documentation.ird.fr/hor/fdi:010040915 10.1016/j.gloplacha.2006.11.036 0921-8181 [F B010040915] https://www.documentation.ird.fr/hor/fdi:010040915 https://www.documentation.ird.fr/intranet/publi/2008/01/010040915.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2008-02-22 2017-08-23 fdi:010040915 fre