Quality control of global solar radiation using sunshine duration hours

The aim of this study was to develop a new and automatic method for controlling the quality of daily global solar radiation, G_d, using sunshine duration hours. The new method has three levels of tests: first, G_d is compared against daily extraterrestrial radiation that is received on a horizontal surface (0.03×G_od?G_d<G_od); second, G_d should only exceed by a small amount of the daily clear sky irradiation that is observed under highly transparent clear skies (G_d<1.1G_cd); and third, the method uses a series of persistence checks that utilize the relation between daily global solar radiation and relative sunshine duration hours. The method is capable of identifying systematic and non-systematic errors and its ability has been shown in three different climates including semi-arid, coastal humid and very arid climates.