Investigating Pléiades imagery for high-resolution topographic analysis in alpine headwater zones

Accurate topographic modeling in steep alpine environments is critical for understanding and monitoring geomorphological processes such as landslides and debris flows. While very high-resolution (VHR) satellite imagery has been widely applied in glaciated regions, its potential for non-glaciated alpine headwater catchments remains underexplored. This study evaluates Pléiades tri-stereo imagery for generating high-resolution Digital Surface Models (DSMs) over two high-relief Alpine catchments. Using the Ames Stereo Pipeline, 27 DSMs are produced from varying stereo pairings, dense-matching algorithms, and kernel sizes. Comparison with airborne LiDAR shows that DSM accuracy is strongly dependent on processing configuration, with the optimized workflow achieving a vertical accuracy of 0.06 ± 0.34m. These results highlight the capability of Pléiades DSMs, when optimally processed, to support hazard mapping and sediment monitoring in complex mountain terrain.