Analysing sky luminance scans and predicting frequent sky patterns in Singapore

A thorough analysis of sky distributions can help in the prediction of daylight patterns and thus provides a good understanding of architectural window and building envelope design. This paper introduces three methods of analysis for sky distributions, namely the relative indicatrix and gradation classification, and two other independent methods established by Kittler and Tregenza. All these three methods were verified for their feasibility for analysing the extreme daylight conditions in Singapore, which is located at the equator. The most suitable approach, from Tregenza, was eventually adopted in analysing the measured data from Singapore IDMP station. The prediction of frequent sky patterns in Singapore was based on the CIE Standard General Skies, as well as a complete version considering all 36 theoretical sky types.

[1]  R. Kittler.  The need for standard skies and models for energy conservation measures , 1994 .

[2]  Edward Ng,et al.  Evaluation of six sky luminance prediction models using measured data from Singapore , 1999 .

[3]  Richard Kittler,et al.  Prevailing sky conditions: Identifying simple parameters for definition , 1997 .

[4]  Richard Kittler,et al.  Luminance distribution characteristics of homogeneous skies: a measurement and prediction strategy , 1985 .

[5]  Richard Kittler,et al.  Some qualities of scattering functions defining sky radiance distributions , 1994 .

[6]  Christian A. Gueymard,et al.  Reference luminous solar constant and solar luminance for illuminance calculations , 2005 .

[7]  Stephen Wittkopf.  Evaluation of Virtual Sky Domes for the Prediction of Daylight Performance with Radiosity-based Light Simulation Software , 2005 .

[8]  P. R. Tregenza,et al.  Analysing sky luminance scans to obtain frequency distributions of CIE Standard General Skies , 2004 .

[9]  Warren G. Julian,et al.  Daylight measurement data: Methods of evaluation and representation , 1992 .

[10]  Stephen Wittkopf,et al.  Prediction of energy savings with anidolic integrated ceiling across different daylight climates , 2006 .

[11]  Richard Kittler.  Relative scattering indicatrix: Derivation from regular radiance/luminance distribution sky scans , 1993 .

[12]  M. B. Ullah.  International Daylighting Measurement Programme — Singapore data I: Quality of data gathered over a long period , 1996 .

[13]  M. B. Ullah.  International Daylight Measurement Programme — Singapore data III: Building energy savings through daylighting , 1996 .

[14]  P. R. Tregenza,et al.  Subdivision of the sky hemisphere for luminance measurements , 1987 .

[15]  Danny H.W. Li,et al.  A Study of 15 Sky Luminance Patterns against Hong Kong Data , 2003 .

[16]  P. R. Tregenza,et al.  Standard skies for maritime climates , 1999 .

[17]  M. B. Ullah,et al.  International Daylighting Measurement Programme — Singapore data II: Luminous efficacy for the tropics , 1996 .

[18]  Stephen Wittkopf.  A Method to Construct Virtual Sky Domes for Use in Standard CAD-based Light Simulation Software , 2004 .

[19]  Richard Kittler,et al.  Sky Classification Respecting Energy-Efficient Lighting, Glare and Control Needs , 1997 .