“…A number of experiments using both ground-based and airborne sensors have shown the high potential of microwave radiometry for monitoring surface soil moisture (Calvet, Wigneron, Chanzy, & Haboudane, 1995;Chanzy et al, 1997;Jackson, Le Vine, Swift, Schmugge, & Schiebe, 1995;Schmugge & Jackson, 1994), particularly at L-band. To date, there is no spaceborne sensor measuring the microwave emission of the soil surface at this frequency, although several new programs are scheduled: the National Aeronautics and Space Administration's projects (see Njoku, Rahmat-Samii, Sercel, Wilson, & Moghaddam, 1999, for instance) and the European Space Agency's SMOS mission . The main objective of the Soil Moisture and Ocean Salinity (SMOS) mission is to deliver important variables for the land surfaces: soil moisture and for ocean surfaces: sea surface salinity fields.…”