Mountain glacier displacement estimation using a DEM-assisted offset tracking method with ALOS/PALSAR data

Abstract

Mountain glaciers, as a sensitive indicator of climate change, are often monitored with all-weather synthetic aperture radar (SAR) technology. In contrast to the differential interferometric SAR approach, which is affected by decorrelation, the offset tracking method is a promising alternative that produces glacier displacement fields directly. The method, however, is often influenced by additional offsets associated with topographic effects in rugged mountain areas. For removing these topographic-related offsets, we present a digital elevation model-(DEM-) assisted offset tracking procedure and employ it with the Advanced Land Observing Satellite (ALOS) Phased Array type L-band SAR (PALSAR) data of Mt. Muztagh Ata. The results demonstrate the advantages of this method by reducing the topographical effects and increasing the accuracy (0.98 m). The approach proposed in this study can increase the accuracy of the results for estimated mountain glacier displacement and also extend the applicable range of the offset tracking method.