Attenuation Factor Estimation of Direct Normal Irradiance Combining Sky Camera Images and Mathematical Models in an Inter-Tropical Area. - Román Mondragón; Joaquín Alonso-Montesinos; David Riveros-Rosas; Mauro Valdés; Héctor Estévez; Adriana E. González-Cabrera; Wolfgang Stremme (Remote. Sens., 2020)