Towards Validation of SMOS Using Airborne and Ground Data Over the Murrumbidgee Catchment

Abstract: With the launch of the European Space Agency’s Soil Moisture and Ocean Salinity (SMOS) satellite scheduled for mid 2009, the first long-term space-borne passive microwave observations at L-band ( ~ 1.4 GHz) will soon be available. Consequently, SMOS will be the first mission dedicated to global mapping of near-real-time surface soil moisture information. Though space-borne microwave instruments have measured global data at high frequencies (e.g. C- and X-band) for the last 20 years, this innovative L-band radiometer will use a new synthetic aperture concept that will provide observations at multiple incidence angles. Consequently, the observed brightness temperature data and derived soil moisture product must be validated. To achieve this, intensive field campaigns are being planned world-wide to support the satellite mission with reliable data from i) passive microwave airborne observations at L-band, ii) detailed ground measurements of surface soil moisture content and associated environmental parameters, and iii) long-term soil moisture monitoring network data from anchor sites (e.g. Murrumbidgee in Australia, Valencia in Spain, Upper Danube in Germany etc.). With the SMOS launch likely to take place in the later part of 2009, Australia is particularly well positioned for conducting the first intensive SMOS validation campaign during its spring. The Australian Airborne Cal/val Experiment for SMOS (AACES) will provide one of the mos