kobavskytype
The kobavskytype function determines the CIE general standard sky type for a given luminance distribution of a Tregenza hemisphere as described by Kobav et al. in “Characterization of sky scanner measurements based on CIE and ISO standard CIE S 011/2003” .
See also: getskytype, tregenzaskytype
Usage:
[sky,RMS] = kobavskytype(L,sunaz,sunel,mode)
Where:
| Parameter | Description |
sky | Returns the best fitting CIE standard general sky as in CIE S 011, determined with Kobav et al. method. |
RMS | Returns the Root Mean Square deviation from the best fitting CIE standard general sky. RMS from gradation and indicatrix determination is averaged. |
L | Defines the Tregenza hemisphere luminance distribution. |
sunaz | Defines the sun azimuth angle \alpha_S. |
sunel | Defines the sun elevation angle \gamma_S. |
mode | Defines the luminance determination mode of the reference data: ’cie’ (default) returns the skytype according to the CIE table. Not all indicatrix and gradation goup combinations result in a skytype, the function will than return a NaN value. ’nearest’ returns the best fitting CIE skytpye. |
Example
Determine CIE skytype at \alpha_S = 166\degree and \gamma_S = 33\degree:
L = ciesky(12,166,33); [sky,RMS] = kobavskytype(L,166,33)
See also: ciesky
Result:
sky = 12 RMS = 0.019045
References
ISO 15469:2004(E)/CIE S 011/E:2003: Spatial Distribution of Daylight – CIE Standard General Sky. Commission Internationale de l’Éclairage (CIE), Vienna Austria, 2004. URL: https://cie.co.at/publications/spatial-distribution-daylight-cie-standard-general-sky
Peter Roy Tregenza: Subdivision of the sky hemisphere for luminance measurements. In: Lighting Research and Technology, vol. 19, no. 1, pp. 13-14, 1987, DOI: 10.1177/096032718701900103. URL: https://journals.sagepub.com/doi/10.1177/096032718701900103
Kobav M, Bizjak G, Dumortier D.: Characterization of sky scanner measurements based on CIE and ISO standard CIE S 011/2003. In: Lighting Research & Technology, vol. 45, no. 4, pp. 504–512, 2012, (DOI: 10.1177/1477153512458916).
URL: https://journals.sagepub.com/doi/10.1177/1477153512458916?icid=int.sj-abstract.citing-articles.1