TERRESTRIAL RADAR INTERFEROMETRY TO MONITOR GLACIERS WITH COMPLEX ATMOSPHERIC SCREEN

This paper reports the results of two terrestrial surveys aimed at monitoring two Alpine glaciers located in Italy and Spain respectively, and carried out using a Ground Based SAR interferometer. Although the monitoring of glaciers based on this technique does not represent a novelty, these two case studies are peculiar, due to the characteristics of the Alpine glaciers among which the dominant role of the atmospheric phase screen (APS) on the radar signal propagation. These kind of glaciers, with their climate and geographical features, often demand a detailed analysis of the acquired data, at small temporal (less than an hour), and spatial (a few square meters) scale. The meteorological conditions, which affect the dynamics of the glaciers, deeply influenced the backscattering behavior, demanding a careful analysis of the amplitude of the radar signal, to characterize the surface, and of the interferometric phase, to evaluate the role of the APS. Only after the correction of the APS, a final accuracy of a few millimeters/day was attained in the daily velocity of the glacier in both cases.