The validation of NO2 columns is based on an end-to-end approach, that has been developed to evaluate independently all critical components of the level-1-to-2 retrieval chain, using correlative observations performed by ground-based and satellite instruments. This includes:
- Comparison with other satellite datasets, including GOME, SCIAMACHY and OMI instruments and other datasets for GOME-2, such as the TEMIS product.
- Direct comparison with ground-based zenith-sky DOAS instruments from NDACC stations;
- Direct comparison with ground-based MAXDOAS and Direct Sun instruments at different BIRA stations or from PGN network.
Information on the NO2 GOME-2 AC SAF operational product and its validation methodology and results can be found in several papers (see below) and in the last validation report.
The last validation result figures are gathered here.