Chain of Algorithms to Calculate Advanced Radiation Parameters

Algorithms linked to form focused chains of algorithms are needed to fill gaps between often measured or available data resources and the parameters requested by many solar applications. This paper describes the formulation of a chain of algorithms for shortwave radiation. The basic inputs into the chain are monthly mean values of the Linke turbidity factor and global radiation. The outputs of the chain are hourly values of global shortwave radiation on inclined planes. This is achieved via stochastic generation of daily and hourly values of global radiation, splitting the global into beam and diffuse radiation and finally calculating the radiation on inclined planes. The cloudless sky chain is based on an improved version of the clear sky model of Rigollier et al. (2000). The stochastic generation process is based on Aguiar et al. (1988, 1992) but important improvements have been made by cross-linking to the clear sky model. The Perez models (1986, 1990) are used for splitting the radiation into its components and for estimating radiation on tilted planes. Datasets produced with the described chains can be accessed via the prototype of the SoDa project at www.soda-is.org.