The Remote Sensing in Research of Modern Glacier Changes

Abstract

Traditional research methods in modern glacier changes mainly based on field observations and empirical formula to calculate changes in glacier area,volume and surface velocity,however,since 1980s,with the new technologies of aerial remote sensing images,digital elevation model,radar,etc.developed,the studies of nature and characteristic of glaciers and detection of dynamic changes in glacier have not only become the important trends of glacier research by means of remote sensing method,but also greatly resolved the problems such as limited information in high mountain areas.The computer-based automatic interpretation methods in the study of glacier area change including threshold and NDSI(Normalized Difference Snow Index),supervised classification and non-supervised classification,threshold value of band ratio,etc.Although the operating of threshold and NDSI are simple,they are difficult to select the suitable threshold on such issues;Non-supervised classification method is simple but more constraints.With the accurate selection of training area,the result of supervised classification method is more accurate.The threshold value of band ratio method is the most widely used computer automatic classification because of its simple operation and accurate result.The application of Digital Elevation Model and radar data in the study of glacier volume change preferably improves the accuracy and applicability of traditional methods.And that radar data will not be affected by atmospheric propagation and climate change compensated for the weak script of remote sensing images data which is easily influenced by snow and clouds.With the development and application of high precipitation GPS and radar data,it plays an irreplaceable role in surface velocity studies.