This document describes the software Heliosat-II developed by the Groupe Télédétection & Modélisation, Centre d'Energétique, a joint research unit of Armines and Ecole des Mines de Paris. The method Heliosat-II was developed by this research group in 2000-2001, partly with the support of the European Commission (project SoDa, contract DG "INFSO" IST-1999-12245, http://www.sodais. com). This method converts images acquired by the satellite Meteosat into maps of global irradiation received at ground level. Under concern are the images acquired in the visible band of the Meteosat sensor. The software was developed in C for a Unix station. The present document describes the various libraries and procedures. It describes how these can be implemented for the correct execution of the whole method. The procedures described here comprise I/O orders that are to be tailored to the specific format for Meteosat images. The method can be applied to other geostationary satellites offering similar broadband in the visible range (0.4 - 1.1 mm). The input images are geometrically superimposable images. Calibration coefficients exist that convert digital counts into radiances (W m-2 sr-1).
