BS ISO 15469:2004
Spatial distribution of daylight - CIE standard general sky

Standard No.

BS ISO 15469:2004

Release Date

2004

Published By

British Standards Institution (BSI)

Latest

BS ISO 15469:2004

Replace

BS ISO 15469:1998

Scope

This Standard defines a set of outdoor daylight conditions linking sunlight and skylight for theoretical and practical purposes. The luminance distributions given have the following characteristics: i. They are symmetrical about the solar meridian and are functions of the angular distance, Zs, between the sun and the zenith. ii. They are defined by smooth continuous functions. Such distributions are typical of cloudless skies and of those where the cloud cover is homogeneous. They provide an approximation to skies of broken cloud that is sufficiently accurate for many practical daylight calculation purposes. iii. The relative luminance at any point in the sky depends on the angle,
, between that sky element and the sun, and on the angle, Z, between the sky element and the zenith. It is given in terms of two functions: the relative scattering indicatrix, f(
), and the luminance gradation between horizon and zenith, (Z).

BS ISO 15469:2004 history

• 2004 BS ISO 15469:2004 Spatial distribution of daylight - CIE standard general sky
• 0000 BS ISO 15469:1998