“CITHARE” thermal inertia and humidity cartography over Africa by geostationary satellite

The study of ground thermal behavior can give fruitful information on subsoil characteristics and soil moisture. Interest in this field has led to the definition of the CITHARE project, whose aim is to determine the feasibility of elaborating significant products for geological and hydrological purposes. The basis for such a study is to utilize many successive IR and visible pictures in order to assess thermal inertia over a given area. For that reason a meterological geosynchronous satellite, such as SMS or METEOSAT, with its high temporal and stable coverage appears as a first choice data source. Results, obtained with a preliminary set of SMS data demonstrate the influence of sensible heat, wind, surface roughness, topography on the determination of thermal inertia. The continuous observation of the Earth is required to properly discriminate such effects for a determination of thermal inertia.