The properties of incident shortwave solar radiation are an essential knowledge in several fields. Global irradiation at ground level can be estimated by processing images taken by geostationnary meteorological satellites in visible channel. Results are more accurate than those provided by a spatial interpolation of ground stations measurements. However, in spite of the satellite data availability for more than 25 years, long term time series of global irradiation offering a world wide coverage and a high spatial resolution do not currently exist. Moreover, satellite-based assessment methods cannot accurately estimate direct and diffuse components, and spectral distribution of solar radiation. There is thus a non-satisfied part of solar data user requirements. In this context, we propose an operational processing of time series of Meteosat images using the solar radiation assessment method called Heliosat II. We disseminate the results by developing an information system called HelioClim-1. This system delivers on-line global irradiation data over Europe, Africa and Atlantic Ocean from 1985 to 2004. We assess the quality of these data and analyse their uncertainties by comparing them with ground measurements. We ensure a temporal continuity of this system by participating on the design of a new method (Heliosat III) benefiting of the Meteosat Second Generation enhanced capabilities and by preparing the specifications of a new information system containing Heliosat III results. This work improve the quality and the accessibility of solar radiation information at ground level by using current satellite tools and new technologies of information and communication. It opens the way to a world-wide coverage of solar radiation information with a good quality and a convenient access.
