Within the QA4EO project a Precision FilterRadiometer (PFR) traveling standard was installed at the European calibration site of AERONET Europe to provide continuous traceability of aerosol optical depth measurements to the World reference of AOD maintained at Davos through a PFR-Triad. The objective is to homogenize the two global monitoring networks of passive remote sensing of aerosol optical properties, which serve as fiducial reference for satellite derived aerosol properties. The PFR traveling standard was installed collaboration of the laboratory of atmospheric optics (LOA,CNRS) at the Observatoire de Haute province (OHP) in southern France in July 2020 and operated continuously with minor interruptions until September 2021. During clear sky periods the measurements of spectral solar irradiance are used to retrieve aerosol optical depth from the master instrument of AERONET-Europe and the PFR. The online comparison (on going activity) can be found in https://www.pmodwrc.ch/en/world-radiation-center-2/worcc/gaw-pfr/ohp/ The dataset consists of the AOD data of the AERONET-Europe ( 20200101_20221231_OHP_OBSERVATOIRE.lev20 ) and the GAW-PFR network ( OHP_PFR_N14_202007_202102.zip ) and the synchronizes common dataset of the Cimel and PFR instruments QA4EO_WP2230_OHP_Campaign_2020_2021_level2.mat. the fields of the matlabfile are described in the corresponding readme file.

The campaign was supported by the ESA project QA4EO, No. QA4EO/SER/SUB/09