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Modeling sky luminescence using satellite data to classify sky conditions


Janjai, S and Masiri, IO and Nunez, M and Laksanaboonsong, J, Modeling sky luminescence using satellite data to classify sky conditions, Building and Environment, 43, (12) pp. 2059-2073. ISSN 0360-1323 (2008) [Refereed Article]

DOI: doi:10.1016/j.buildenv.2007.12.009


A model for calculating sky luminance is presented. The earth–atmospheric reflectivity obtained from satellite data was used to classify sky conditions. The proposed sky luminance at a specific point in the sky hemisphere is a product of two functions, namely F1 and F2. For any point in a sky hemisphere, F1 varies with the sky zenith of the considered point (Z) and F2 is a function of the angular distance between the considered point and the sun (÷). The model uses simultaneous measurements of sky luminance and GMS-5 satellite observation, both taken at Nakhon Pathom, Thailand (13.70°N, 103.10°E), during November 2002 to May 2003. Both F1 and F2 are derived as polynomial functions of ÷, Z and the solar zenith angle (Zs) for each sky condition. The classification of the sky condition is based on the satellite-derived earth–atmospheric reflectivity. This sky luminance model was validated against independent measurements from the Asia Institute of Technology (AIT) (14.08°N, 100.62°E). The root mean square difference (RMSD) between the relative sky luminance calculated from the model and that obtained from the measurement is 0.133.

Item Details

Item Type:Refereed Article
Keywords:Sky luminance; Satellite data; Sky scanner; Earth–atmospheric reflectivity; Daylight
Research Division:Earth Sciences
Research Group:Climate change science
Research Field:Climatology
Objective Division:Environmental Management
Objective Group:Air quality, atmosphere and weather
Objective Field:Air quality, atmosphere and weather not elsewhere classified
UTAS Author:Masiri, IO (Mr Itsara Masiri)
UTAS Author:Nunez, M (Dr Manuel Nunez)
ID Code:55045
Year Published:2008
Web of Science® Times Cited:18
Deposited By:Geography and Environmental Studies
Deposited On:2009-03-04
Last Modified:2009-03-19

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