W. PALZ, Commission of the European Communities, Directorate-General for Science, Research and Development, Brussels STRATEGY PAPER EC SOLAR ENERGY R&D PROGRAMME Project F, Solar Radiation Data - OUTLINE (Status as of April 1981) 5 ACTION 1 -Calibration and characteristics of radiometers J. -L. PLAZY, Commissariat a l'Energie Solaire, Sophia Anti- polis, Val bonne, France 11 ACTION 2 -Short reference years H. LUND, Thermal Insulation Laboratory, Technical University of Denmark, Lyngby, Denmark 19 ACTION 3 -ATLAS AND DATA BOOKS (from existing data) ACTION 3. 1 - Global irradiance on horizontal plane - Definition of radiation climate zones in the EC F. KASTEN, Deutscher Wetterdienst, Meteorologisches Obser- torium Hamburg, Federal Republic of Germany 28 ACTION 3. 2 - Global irradiance on tilted planes - Direct radiation R. DOGNIAUX, Institut Royal Meteorologique de Belgique 37 ACTION 3. 3 -Statistical analysis of meteorological data J. A. BEDEL, Direction de la Meteorologie, Service Meteoro- gique metropolitain, Paris, France 53 ACTION 3. 4 -Sensitivity analysis of the useful energy output for solar converters with respect to quality and completeness of meteorological data sets H. R. KOCH, KFA Julieh, Institut fUr Kernphysik 74 ACTION 4 -NEW MEASUREMENTS AND TECHNOLOGIES ACTION 4. 1 -Improvement of measurements in national network- global, direct, diffuse irradiance and irradiance on inclined surfaces J. W. GRUETER, Kernforschungsanlage Julich, Federal Republic of Germany 92 ACTION 4. 2 - Special measurements J. -L.