**7. References**


**8** 

 *Slovakia* 

**Parameterisation of the Four Half-Day** 

*Institute of Construction and Architecture, Slovak Academy of Sciences, Bratislava,* 

The International Commission on Illumination (C.I.E) in its Technical Committee TC 3-08 for Daylight initiated in 1983 the so called International Daylight Measurement Programme (IDMP). This programme was officially launched by the CIE President Bodmann (1991) and several CIE IDMP stations were established world-wide and now relatively long-term regular data are available for studies and analysis (Kittler et al., 1992). Although some daily courses served to characterise luminance sky patterns and local daylight climate, there are possible more detail analysis of half-day situations with relation to sunshine duration, cloudiness and turbidity influences parametrised. This chapter tries to show the theoretical basis with documented applications using examples of several parametrised evaluations of measurements taken at the Bratislava and Athens CIE IDMP general stations which can be taken as instructing samples to be imitated using local measured data. The aim is also to show how momentary illuminance values correspond with hourly averages under four different daylight situations and how these half-day situations can be simulated when only monthly relative sunshine duration is available and when monthly or year-round random

daylight conditions are needed and could be approximated.


and West *GvvW* excluding the ground reflection.


**2. Regular daylight measurements and their possible analysis** 

Since the CIE (2003) and ISO (2004) fifteen general homogeneous sky luminance patterns were standardised many CIE IDMP (International Daylight Measurement) stations recording regularly long-term daylight parameters try to evaluate the frequency of typical skies in their localities. Because the general CIE IDMP stations without sky luminance scanners sometimes do not record even zenith luminance *Lvz* simultaneously with diffuse skylight illuminance measurements *Dv* there are missing either sky scans or the classifying parameter *L D vz v* / , which could identify the momentary sky type. Thus, usually are only available data of


regularly measured illuminance parameters in one minute steps during daytime, i.e.:

**1. Introduction** 

**Daylight Situations** 

Stanislav Darula and Richard Kittler

