ESA leads the way to map boreal forest   A boreal forest stand within the Krycklan site in northern Sweden. Boreal forest covers about 15% of the Earth’s land surface. The boreal region forms a circumpolar band throughout the northern hemisphere, extending through Russia, Northern Europe, Canada and Alaska. The great expanse and large amount of carbon contained in vegetation and soils (particularly peat) make the boreal biome the world's largest terrestrial carbon reservoir.   The objective of the candidate Earth Explorer BIOMASS mission is to acquire global measurements of forest biomass to assess terrestrial carbon stocks and fluxes. The mission is envisaged as a novel spaceborne P-band synthetic aperture polarimetric radar operating at 435 MHz and 6 MHz bandwidth.   Scientists from the Swedish Defence Research Agency (FOI) poring over forest maps. Activities on the ground to record the characteristics of the forest stands take place in parallel with the airborne acquisitions. They are used to validate the interpretation and retrieval algorithms applied to the Synthetic Aperture Radar images.   The Dornier-228 carrying the DLR airborne radar system at Umeå airport, Sweden   Aligning a huge 5m corner reflector during the BioSAR 2008 campaign. The reflector gives a strong and immediately identifiable signal in the radar images and is used to calibrate and assess data quality. However, it needs to be aligned carefully with the flight direction of the airborne SAR system.   View of the Krycklan test site in northern Sweden Release date: 3 December 2009