Alpine glaciers act as freshwater reservoirs and are recognized as sensitive indicators of climate fluctuation. Monitoring glacier changes is therefore important for both hydrological applications and climate change studies. The glacier mass balance, i.e. the sum of all processes which add (e.g. snow fall) or remove mass from glaciers (e.g. snow or ice melting), is a key parameter for these applications. As the climate changes, this balance may be altered.
The glacier cover map product identifies glacier extent and cover type, discriminating snow, ice, firn and bare soil. The snow line, i.e. the line separating snow from bare ice or firn, can be retrieved from these maps. At the end of the ablation period, the late summer snowline altitude can be interpreted as an approximation of the equilibrium line altitude (ELA). The ELA is the line that separates the accumulation from the ablation areas. It corresponds to the theoretical line where the net mass balance equals zero within a particular year. Given its high correlation with the annual mass balance, the ELA is an important proxy variable for mass balance estimation.
The glacier cover map product is realized through a multi-temporal approach based on Hidden Markov Model (HMM) and Support Vector Machine (SVM). This methodology can be applied for a single sensor dataset (e.g. Sentinel-1) or can be employed for integrating different sensor time series (e.g. Sentinel-1 and Sentinel-2).
