PNNL

Abstract

Sky models in daylight simulations represent the luminance variation across the sky-dome for different locations, date, time, and weather conditions, but skies are typically modeled as colorless. Recent studies explore techniques for incorporating the spectral content of daylighting in simulations. The objective of this paper is to provide an evaluation of the existing spectral sky models in lighting simulation software. The comparisons are made between the available mathematical sky models and naturally occurring skies that were recorded using High Dynamic Range (HDR) photography and spectrophotometric measurements. The results show that currently available sky models present progress in comparison to colorless sky models, but further research is needed to develop reliable spectral sky models.