Controllo delle fluttuazioni dei ghiacciai alpini mediante telerilevamento da satellite

Satellite monitoring of Alpine glacier fluctuations

Abstract

Landsat digital images are processed by an interactive computer program (ISIID) from which information on glacier surface and morphology is obtained. The proposed method uses MSS (Multi Spectral Scanner) bands of visible and near infrared spectrum. It identifies standard bands 5 and 7 to get the best insight of both total and snow free glacier surfaces. The method for digital images interpretation and glacier identification has been implemented by comparing the radiance maps with the ground topography; in particular the fixed structures along glacier boundaries were exploited. The digital image analysis is organized in four steps: pre-processing; total glacier and snow free glacier surfaces identification; recognition and classification of both accumulation basins and frontal areas by utilizing elevation data along glacier boundaries; multitemporal comparison of glacier surfaces using the coordinates of the fixed structures. By means of these techniques, glacier surfaces of Mount Disgrazia (Alpi Retiche, Italy) have been compared for different years to estimate frontal and snow line fluctuations.