International audienceThe European Soil Moisture and Ocean Salinity (SMOS) mission, after some delay now planned for launch late 2008, will carry a two-dimensional L-band (1.4 GHz) microwave interferometric radiometer with a revisit time smaller than 3 days to retrieve soil moisture (and ocean salinity) at global scale with a spatial resolution of similar to 30km. Soil moisture plays a crucial role in the terrestrial hydrological cycle and its timely and repetitive retrieval is essential for medium term meteorological modelling, hydrological modelling and modelling of several other climate related processes such as vegetation biomass production and CO2 assimilation. Repetitive monitoring of soil moisture fields at regional scales, also are ...