Elevation changes and X-band ice and snow penetration inferred from TanDEM-X data of the Mont-Blanc area

In this paper, we process TanDEM-X scenes, acquired between May 2012 and November 2013, with the use of a high-resolution DEM obtained from Pléiades images, to derive 5 new DEMs in the Mont Blanc area, by mean of differential radar interferometry (D-InSAR). The vertical precision of the DEMs estimated off ice is in the range 1.92–3.10 m. The comparison between the DEMs derived from optical and radar sensors at close dates allows use to estimate the penetration of the radar signal into snow and ice. It can reach 7 m in dry snow and ice, for elevations higher than 3500 m in October and 2500 m in February. This difference must be taken into account when deriving glaciers mass balance, especially over short periods.