BS ISO 15469-2004 日光的空间分布.CIE标准普通天

标准号：BS ISO 15469-2004
中文标准名称：日光的空间分布.CIE标准普通天
英文标准名称：Spatial distribution of daylight - CIE standard general sky
标准类型：F12
发布日期：2004/4/5 12:00:00
实施日期：2004/4/5 12:00:00
中国标准分类号：F12
国际标准分类号：17.180.20
适用范围：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).