The PEGASOS project: Evaluation of Geo-Ring data with LEO and ground based measurements

The PEGASOS project (Product Evaluation of GEMS L2 via Assessment with Sentinel-5P and other Sensors) provides comparisons for GEO L2 data with measurements from LEO instruments and ground-based networks. The main focus is on the evaluation of the operational GEMS and TEMPO L2 data products total Ozone, tropospheric and stratospheric NO2, as well as cloud- and aerosol parameters like cloud fraction, cloud pressure, aerosol index and aerosol layer height. For the evaluation of those GEMS and TEMPO L2 products, comparisons with space-borne instruments rely mainly on TROPOMI/S5P and GOME-2/MetOP-BC, and on ground-based measurements/networks like Dobson, Brewer, Max-DOAS etc.
In this contribution we provide an overview of the current PEGASOS project status and we summarize the activities performed so far for evaluating the GEMS and TEMPO L2 data products mentioned above. The ESA-funded PEGASOS project is coordinated by the German Aerospace Center (DLR) and the consortium is completed by the Aristotle University of Thessaloniki (AUTH), the Royal Belgian Institute for Space Aeronomy (BIRA-IASB), and the Institute for Environmental Physics of the University of Bremen (IUP-UB).