 The new satellite-based CMSAF-SERRA, Solar Surface Radiation Alliosat, data record provides accurate and reliable measurements of solar surface radiation, making it ideal for regional climate monitoring and analysis, as well as for solar energy applications. Compared to its predecessor, the CMSAF very climate data record, SERRA has shown significantly improved accuracy and homogeneity. This article was authored by Richard Muller, Uvap Feefroth, Christine Traker-Chatterjee, and others.