OPERA-SMS

The Sentinel-4 UVN instrument has been launched on 1st July 2025 to a geostationary orbit as part of the Meteosat Third Generation – Sounding (MTG-S) satellite system, and is currently in its commissioning phase. It is the first instrument of its kind to provide hourly measurements of air quality over Europe and contributes to the Copernicus initiative for advanced atmospheric monitoring. Sentinel-4 will allow an unprecedented analysis of the diurnal variations of key atmospheric constituents affecting air quality. This includes key indicators like NO₂, O₃, SO₂, HCHO, CHOCHO as well as cloud-, aerosol-, and surface properties, which are all products that are crucial for air quality monitoring, climate research, and environmental policy support. These data products are generated by so-called Level 2 processors: a set of sophisticated retrieval algorithms which provide physical information about the atmosphere in near-real-time and in an automated operational environment. The Level 2 processors are responsible for converting calibrated top-of-atmosphere radiance and solar irradiance satellite data into the aforementioned geophysical products. Under a EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites) contract, DLR is leading as prime contractor the OPERA-SMS (Operational ramp-up support and maintenance service) project. The international OPERA-SMS consortium consists of scientific and technical experts for the retrieval of atmospheric air quality data and the development, maintenance and evolution of the Level 2 processors.