Coupling digital terrain to radiative transfer model to assess surface solar radiation at high resolution scale: validation of GIS module r.sun in Galicia

Abstract

When estimating solar radiation at regional scale, topography plays a very important role as it modifies radically the spatial distribution of insolation. For this reason, radiative transfer models need to be coupled to a digital terrain model. This work pretend to validate one of the most outstanding GIS tools with the complex Galician topography. Several data proceeding from different satellites were used as inputs. The accuracy of r.sun module was tested for both cloudless and overcast conditions. The results achieved point out the good accuracy of r.sun, especially under clear skies.