Panagiotis provided a full overview of the ground based radiometric instrumentation of APCG and both the services and research objectives that the instruments are involved in. From investigating the influence of NO2 on the AOD estimation, to the delivery of water vapor, aerosol and trace gases products and the evaluation of the Pandora TROPOMI NO2 column, it was evident that great job has already been done and great potential exists, especially in creating stronger synergies with the in situ and modeling activities of the group. Way to go Panagiotis and many thank to Dr. Stelios Kazadzis for his continuous scientific support from PMOD/WRC.