Energy and water vapour fluxes are important factors for the understanding of terrestrial ecosystems. While meteorological measurements provide necessary information for selected locations, an upscaling of the fluxes requires additional information, especially for heterogeneous environments like the polygonal tundra landscape. Spaceborne Synthetic Aperture Radar (SAR) is a valuable tool as it works independent from cloud cover and sunlight. SAR data can be used to determine spatial and temporal distribution of parameters such as soil moisture, changes in vegetation, timing of snowmelt during spring, freezing of active layer during autumn, and freezing and thawing of lakes, ponds and river arms.