MONTH-TO-MONTH VARIATION OF GLOBAL SOLAR RADIATION IN CATALONIA (SPAIN)

Daily data of global solar imdiation on a horizontal surface for various time periods within the years 1964-1 993 collected from 57 stations in and around Catalonia (Spain) have been filtered and treated in order to construct the annual and monthly solar radiation maps that compose the Solar Radiation Atlas of Catalonia. Emphasis has been given to the data filtering process. The methodology developed for this purpose is described. Data treatment, based on a simple model, is also described and justified. Finally, diffuse irradiation measurements performed at four stations in the Catalonia basin, are presented.