ISO/CIE standard general Sky represents a set of fifteen types of homogeneous skies used for more accurately description of the exterior daylight conditions based on a distribution of sky luminance by the use of gradation function and functions of scattering indicatrix. The model distinguishes five types of overcast sky, five of cloudy or partly cloudy with the sun seen through a five types of clear sky with different level of atmosphere turbidity. Luminance distribution can be calculated by the use of CIE Standard General Sky model in relative and absolute values, i.e. in cd/m2.
▼Kittler R., Perez R., Darula S. A new generation of sky standards. The 8th European Lighting Conf. Lux Europa 1997, Amsterdam. Conf. Arnhem: Office NSVV, 1997, p. 359-373.
http://www.ustarch.sav.sk/wp-content/uploads/kittler_newsky_luxeuropa97.pdf
▼Kittler, R., Perez, R., Darula, S., A set of standard skies. Bratislava: Polygrafia SAV, 1998. 52p. Republished in
http://www.ustarch.sav.sk/ustarch/download/A_set_of_standard_skies.pdf
▼Darula, S., Kittler, R. CIE General Sky standard defining luminance distributions. Proc. Conf. eSim 2002.The Canadian conference on building energy simulation. September 11th – 13th, 2002, Montreal, Canada.
http://www.ustarch.sav.sk/ustarch/download/Darula_Kittler_Proc_Conf_eSim_2002.pdf
http://mathinfo.univ-reims.fr/IMG/pdf/other2.pdf
▼ISO 15469:2004(E)/CIE S 011/E:2003. Spatial Distribution of Daylight – CIE Standard General Sky. ISO Geneva 2004/ CIE Central Bureau, Vienna 2003.