Estimation of Solar Radiation Using SARAH Satellite Radiation Data in the Northwest of Iran

Accurate determination of the amount of incoming solar radiation at Earth’s surface is important for both climate studies and solar power applications. Satellite-based datasets of solar radiation offer wide spatial and temporal coverage, but careful validation of their quality is a necessary prerequisite for reliable utilization. In this study, daily SARAH satellite data was used to estimate daily solar radiation at weather stations in northwest Iran in 2009 and 2010. According to the results, SARAH radiation data had a high accuracy in estimating solar radiation at all five stations. At the Tabriz station, the error of estimation of radiation was less than that of other stations. According to GSD evaluation criteria, in each station, the estimation error in summer and winter was the lowest (GSD = 6.2 - 12.5) and the highest (GSD = 18.2-25.2) respectively. The results showed that factors such as topography and snow cover affect the accuracy of SARAH radiation data estimation.