As in most European countries, Air Quality (AQ) monitoring in Belgium has hitherto been relying mostly on in-situ measurements of near-surface concentrations, with geographical gaps between observations filled in with numerical models. However, a new global constellation of satellite sounders is being built to support detailed monitoring of AQ on the different relevant scales. As part of the Copernicus programme, the EC is contributing with Sentinel-5 Precursor TROPOMI (Low-Earth Orbit, LEO, since 2017) and the upcoming Sentinel-4 (geostationary, GEO) and Sentinel-5 (LEO) missions. While offering near-contiguous observations of the entire domain (cloud cover permitting), observations from space also imply substantial challenges in terms of (1) spatial resolution (e.g., to resolve the Low Emission Zones), (2) relation between observed vertical column amounts and near-surface concentrations, and (3) synergistic use of multiple satellites with different observing geometries. The aim of the LEGO-BEL-AQ project was to facilitate the use of this new-generation satellite AQ data by institutional policy makers and other stakeholders by advancing on the challenges identified above, with specific applications to the Belgian domain. Specifically, we demonstrated that policy-relevant features in the NO2 distribution over major cities can be obtained with superresolution techniques, trading short-term temporal for spatial information. A synergistic use of satellite and in-situ data (using Regression Kriging) allows a pragmatic conversion from tropospheric columns to near-surface concentrations over the complete Belgian domain, and consequently also a confrontation to, e.g., the WHO annual exposure limit guideline of 10 microgram/m3 at the level of municipalities. Reaching the stakeholders implies a need for specific tailoring of the data and their presentation, and the use of communication channels not usually followed by the Earth Observation community.