The Copernicus atmospheric Mission Sentinel-4: Status of algorithm developments for the L1b and L2 processors

The Copernicus missions Sentinel-4 (S4) and Sentinel-5 (S5) will carry out atmospheric composition observations on an operational long-term basis to serve the needs of the Copernicus Atmosphere Monitoring Service (CAMS) and the Copernicus Climate Change Service (C3S).

Building on the heritage from instruments such as GOME, SCIAMACHY, GOME-2, and OMI, S4 is an imaging spectrometer instruments covering wide spectral bands in the ultraviolet and visible wavelength range (305-500nm) and near infrared wavelength range (750-775 nm). S4 will observe key air quality parameters with a pronounced temporal variability by measuring NO₂, O₃, SO₂, HCHO, CHOCHO, and aerosols over Europe with an hourly revisit time.

A series of two S4 instruments will be embarked on the geostationary Meteosat Third Generation-Sounder (MTG-S) satellites. S4 establishes the European component of a constellation of geostationary instruments with a strong air quality focus, together with the NASA mission TEMPO and the Korean mission GEMS.

This paper will address the development status of the L1b Operational Processor (L1OPS) by EUMETSAT and the supporting L1b reference processor (L1RP) developed by ESA; In dedicated cases (e.g. CTI, Non-linearity signal loss, ...) the algorithms input from the S4 Industrial Prime have been used. The paper will also provide an overview of the status of the Level 2 processor developed by ESA for integration into the EUMETSAT MTG-S ground segment.