Diffuse radiation from the sky dome is typically divided into several components:
- the isotropic component, which represents the uniform irradiance from the sky dome;
- the circumsolar diffuse component, which represents the forward scattering of radiation concentrated in the area immediately surrounding the sun;
- the horizon brightening component.
Published models use different semi-empirical approaches for estimating the combination of these components.
Content contributed by Sandia National Laboratories