Modelling solar irradiance from ground-based photometric observations Theodosios Chatzistergos, Ilaria Ermolli, Fabrizio Giorgi, Natalie A. Krivova and Cosmin Constantin Puiu J. Space Weather Space Clim., 10 (2020) 45 Published online: 30 September 2020 DOI: 10.1051/swsc/2020047