The SMOS project (ESA/CNES), to be launched at the beginning of 2008, aims at developing a spaceborne L band interferometric radiometer able to provide global estimates of surface soil moisture with a sampling time of 2-3 d. Passive microwave remote sensing may provide quantitative information about the water content of a shallow near-surface soil layer. Once the SMOS data will be available at a global scale (spatial resolution of 30-50 km), ground truth measurements of soil moisture, covering large aridity gradients (several hundreds of km), would permit to validate the SMOS products.
SMOSMANIA (Soil Moisture Observing System - Meteorological Automatic Network Integrated Application) is a project aiming at implementing soil moisture measurements in a portion of the automatic ground station network of Météo-France (the RADOME network).
A software development study was performed in order to update the programming of the Xaria stations of RADOME. The SMOSMANIA network will permit to monitor soil moisture in southwestern France thanks to in situ automatic, real-time measurements of soil moisture profiles (-5, -10, -20, -30 cm). Twelve ground stations were activated in 2006 forming a Mediterranean-Atlantic transect of about 300 km.
For the first time, automatic measurements of soil moisture will be integrated in an operational meteorological network.
The 12 station transect was equipped with ThetaProbes. The ThetaProbes are able to perform continuous half-hourly measurements of the volumetric moisture of the soil. They can be buried at different depths. The ThetaProbes have been implemented in 2006 so that the full 2007 annual cycle will be available for the calibration of the ThetaProbes, before the launch of SMOS. In 2007, soil temperature probes will be installed and the calibration of the soil moisture probes will be finalised.
SMOSMANIA (2008-2012) will be a long-term data acquisition effort, before and after the launch of SMOS, to support the validation of the mission. These data will be used to validate the SMOS products. They will contribute to analyse and reduce the bias between the SMOS products and the operational models, a first step before assimilating the SMOS data.
This ground network will be associated with modelling activities in the SIM platform.
HyMeX – Hydrological cycle in the Mediterranean Experiment 2010-2020