Satellite

Biography

Biography: George Kordzakhia

Abstract

The variations in glaciers are the important indicators of regional climate change. The research of glacier melting is important for studies of sea/ocean level changes. Satellites earth observations (EO) are powerfool tool that allow creation of glacier’s data sets with needed regularity. The accurate determination of the glaciers characteristics needs precize definition of glaciers counturs. Glaciers contours automatic determination is based on different spectral properties between the ice and snow by a combination of different spectral channels from visible and infrared range.Satellite data processing, first of all, means radiometric calibration of the satellite specific channels. For glacier research it is necessary to use: i. Slope gradient calculations on the bases of Aster DEM; ii. Slope exposure and the illumination of the highlights of the glacier region. Article presents results of determination of snow line altitude from satellite (EO) data for certain glaciers of Great Caucasus, in the eastern part of Georgia. Landsat-8 OLI TIRS images for the end of ablation period were used to identify snow line position. Snow line altitude was extracted from Advanced Spaceborne Thermal Emission and Reflection Radiometer digital elevation model (Aster DEM). For simplicity the glacier are classified into three classes, which correspond: the first and second - accumulation zone, third - the ablation zone. The border line between accumulation and ablation zones refers to snow line. Using the DEM glacier, band ratios and NDSI calculations snow line heights are determined.