All Sky Model as a standard sky for the simulation of daylit environment

Graphical Representation of Climate-Based Daylight Performance to Support Architectural Design

“…This sky model has been validated for diverse climate and sky zones (sun proximity) (Perez and others 1992;Littlefair 1994;Chaiwiwatworakul and Chirarattananon 2004) and compared with several other models. Comparison results vary from one study to another, but the ASRC model always gives good results, sometimes even better results than the more complex "all-weather sky model", also developed by Perez (Perez and others 1993) and validated with several other models (Perez and others 1993;Littlefair 1994;Chaiwiwatworakul and Chirarattananon 2004;Igawa and Nakamura 2001;Igawa and others 2004). According to Perez (Perez and others 1992), the good performance of the ASRC model is due to the two-fold parameterization of insolation conditions which help differentiate between sky clearness and sky brightness.…”

Modeling the aerosol effects on the light field below a tubular-pipe: A case of clear sky conditions

“…Since the instantaneous luminance maps are scarcely available or difficult to measure routinely a set of empirical models are traditionally adopted to imitate the optical behaviors of natural skies (Perez et al, 1993;Igawa and Nakamura, 2001;Igawa et al, 2004;Kittler, 1999). Such all sky models are partially or fully homogenized and thus do not reflect heterogeneities of luminance patterns typically observed under broken cloud arrays.…”

Blurring the boundaries between Standard General Sky types due to multiple scattering of light

“…2,3 To mimic such a wide range of sky states and to predict the daylight availability successfully, a set of all-sky models have been introduced in the past. [4][5][6] For instance, the current ISO 7 and CIE 8 standards are used to classify the skies into 15 categories using free parameters. Although the transition from overcast, through partly cloudy, to very clear sky is characterised by a discontinuous change of free parameters, the sky conditions typically change smoothly.…”