1 Introduction The continuous and accurate monitoring of solar radiation is essential to determine variations in the composition of the atmosphere and its role in climate change. The spectral distribution of the radiation provides valuable information about aerosols (Grassl, 1971), nitrogen dioxide (Cede, 2006; Zuber et al., 2021) and greenhouse gases such as carbon dioxide, tropospheric ozone and water vapor (Shivers et al., 2019).