The spectral distribution of solar radiation at the earth's surface—elements of a model
Journal article, 1978
The attenuating properties of the atmosphere are presented in a form that permits the calculation of direct, diffuse and global spectral solar irradiance at ground level, using the extraterrestrial irradiance values of Thekaekara. Input data describing the state of the atmosphere are obtained from standard meteorological information or from tabulated average values. Clear sky diffuse spectral irradiance on a horizontal surface is estimated from the direct beam by means of an empirical simplification. Examples of the agreement between calculated and measured values are shown.