In this study Heliosat-2 method was used to derive the ground surface GHI in the United Arab Emirates. Inputs to the model were monthly Linke turbidity factor normalized to an air mass of 2 and a cloud index derived from SEVIRI sensor onboard the European satellite Meteosat. The Linke turbidity factor was obtained from a ground network of seven stations distributed across the UAE. A SEVIRI-based technique was developed and used to derive cloud index from high-resolution visible channels. Ground surface GHI measurements were collected from four inland stations for a period ranging from mid-2007 to mid-2010. The obtained results show that the Heliosat-2 model underestimates the GHI. The obtained root mean square error (RMSE) and mean bias error (MBE) values ranged from 16.3%to 18.5%and 鈭?3.6%to 鈭?5.8%, respectively. A constant bias was observed between modeled and measured GHI throughout the four stations. To correct this bias, the empirical equation used in Heliosat-2 to estimate the clear sky diffuse horizontal irradiance (DHIclear) was recalibrated. With the new DHIclear empirical equation, the modified Heliosat-2 model becomes more adapted to desert and dusty environments such as that of the UAE. By applying the modified DHIclear equation, the RMSE and MBE values dropped to 9.5-10.3%and 鈭?.2 to +0.8%, respectively.