Verhoelst T., Compernolle S., Pinardi G., (…), Gratsea M., (…), Yela González M., Zehner C., Ground-based validation of the Copernicus Sentinel-5P TROPOMI NO2 measurements with the NDACC ZSL-DOAS, MAX-DOAS and Pandonia global networks, Atmospheric Measurement Techniques, 14(1), 481 – 510, 2021. DOI: 10.5194/amt-14-481-2021