The main objective of the Sentinel-4 mission is to monitor key air quality trace gases and aerosols over Europe in support of the Copernicus Atmosphere Monitoring Service (CAMS) at high spatial resolution and with a fast revisit time.

The mission is part of the European Earth Observation Programme "Copernicus" which is run by the European Union together with the European Space Agency (ESA) in ccoperation with the European Environment Agency (EEA).

The Copernicus Space Component comprises a series of space-borne dedicated missions called 'Sentinels' and is developed and procured by the European Space Agency. The missions Sentinel-4, -5 and -5 precursor (S4, S5, S5P, respectively) are conceived as complementary elements of a constellation serving the specific needs of the CAMS. The geostationary S4 mission will provide hourly data on tropospheric constituents over Europe mainly for air quality applications. The target species of the SENTINEL -4 mission include the key air quality parameters NO₂ (nitrogen dioxide), O₃ (ozon), SO₂ (sulfur dioxide), HCHO (formaldehyde), CHOCHO (glyoxal), and aerosols. Complementarily, the Low Earth Orbiting (LEO) missions S5 and S5p will deliver the S4 target species and additionally CO (carbon monoxide), CH₄ (methane), and stratospheric O₃ (ozone)with global daily coverage for climate, air quality, and ozone/surface UV applications.

The Space Segment of the Sentinel-4 mission consists of an Ultraviolet-Visible-Near-Infrared (UVN) light imaging spectrometer instrument embarked on the Meteosat Third Generation Sounder (MTG-S) satellite.

Airbus Defense and Space is the prime contractor responsible for the development of Sentinel-4.

This Handbook provides a high-level description of the Sentinel-4 mission in all its main aspects and contains the following main sections:

• Mission Overview: which provides a brief description of the heritage missions and the main thematic areas and services of the Sentinel-4 mission (e.g. air quality, climate, ozone).

• Mission Objectives: where the main objectives of the Sentinel-4 mission are described.

• Satellite Description:  which briefly describes the MTG-S satellite, including communication links, orbit characteristics, geographical coverage.

• Ground segment architecture: the Sentinel-4 instrument is managed via the MTG ground segment which acts as a Copernicus ‘contributing missions' ground segment

• Instrumental payload: which provides the main characteristics of the Sentinel-4 instrument.

• Data Products: which identifies all data products available from the Sentinel-4 instrument.