1. Barth J, Cadet J, Césarini JP, Fitzpatrick TB, McKinlay A, Mutzhas M, Pathak M, Peak M, Sliney D, Urbach F (1999) TC 6-26 report: Standardization of the terms UV-A1, UV-A2 and UV-B, CIE 134-1999 ISBN 3-900-734-94-1
2. Batlles FJ, Olmo FJ, Alados-Arboledas L (1995) On shadowband correction methods for diffuse irradiance measurements. Solar Energy 54(5):105–114
3. Drummond AJ (1956) On the measurement of sky radiation. Arch 602 Meteor Geophys Bioklim B 7:413–436
4. Gueymard C (1995) SMARTS2: a simple model of the atmospheric radiative transfer of sunshine: algorithms and performance assessment. FSEC-PF-270-95, Florida Solar Energy Center
5. Gueymard C (2003) SMARTS2 code, versión 2.9.2. User’s Manual, Solar Consulting Services Bailey CO. Available from http://rredc.nrel.gov/solar/models/SMARTS/smarts_index.html