id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
ap-1057	Khalil, S. A.; Fathy, A. M.	An Empirical Method for Estimating Global Solar Radiation over Egypt	2008	6	.pdf	application/pdf	3441	117	59	2 Methodology The original form, proposed by Angstrom, expressed the correlation between clear sky global solar radiation and sun- shine duration as follows: G G a b S Nc� �{ ( )}. List of symbols Gc clear sky global solar radiation in kW/m2, S sunshine duration in hours, N length of the daylight in hours, G0 extraterrestrial solar radiation on a horizontal sur- face in kW/m2, E0 correction factor of the Earth’s orbit, � sunrise/sunset hour angle, dn day number in the year (1 365� �dn ), � declination of the sun, � latitude of the station, � day angle in radiance, RMSE root mean square error, MBE mean bias error, n number of data pairs, � % absolute percentage error, Gm measured values of global solar radiation, Ges estimated values of global solar radiation.	cache/ap-1057.pdf	txt/ap-1057.txt