The BIOMASS mission
ESA’s forest mission, BIOMASS is the first satellite to carry a P-band Synthetic Aperture Radar (SAR), in combination with polarimetric and interferometric capabilities. With an exceptionally large antenna of about 12 m diameter, BIOMASS generates a wavelength 70 cm long. Its radar signal will penetrate through the whole forest layer, seeing the larger elements of the tree (like trunk and branches, constituting a significant amount of biomass) and transparent to canopy leaves. The signal scattered back will therefore carry information about the forest structure that can be used to infer parameters such as forest biomass and forest height. Additionally, the mission will have a specific experimental tomographic phase to provide 3D views of forests.
Forests, especially in the tropics, represent a major sink of carbon dioxide. However, the spatial distribution of forest carbon stocks and related fluxes is not yet well-quantified. Above-ground biomass (AGB) in forests, which contains about 50% of carbon, is a central factor in the carbon budget, but in many parts of the planet AGB is poorly quantified due to the difficulty in collecting sufficient field measurements. Moreover, forest degradation and deforestation are causing release of the stored carbon back into the atmosphere, with negative impact on the ecosystem. Information from the BIOMASS mission will hopefully lead to a better understanding of the state of Earth’s forests, how they are changing over time, which quantitative role they play in the carbon cycle.