Evaluation of a terrestrial photogrammetry method for the study of high mountain dynamics. Quebrada del Medio rock glacier, Mendoza, Argentina
Résumé
This paper investigates the potential and limits of terrestrial photogrammetry for studying rock glacier dynamics, and more especifically its interannual surface changes. Using a rather simple digital photogrammetric workflow, the restitution of two 3D-models was done thanks to multi-correlation of more than 100 images acquired in summers 2013 and 2014 on an active rock glacier in the Argentinian Andes. The quality of the output datasets is evaluated by comparing to GPS data, collected on artificial targets (XYZ) and along tracks (Z). Based on this results, we can consider ± 0.24 m as the margin of error that has to be taken into account to assess the surface changes between the two DEMs. Vertical differences affecting the rock glacier front over the one- year time lapse can then be quantified and interpreted in terms of geomorphological processes.