Sentinel-5 Precursor Data Products
Fehr, Thorsten1; Ingmann, Paul2; Nett, Herbert2

The Sentinel-5 Precursor (S5p) mission will address requirements identified by the Copernicus/GMES Atmospheric Services. It will be the first of three ESA Sentinel missions launched, which are dedicated to the observation of atmospheric chemistry and composition. As a precursor to Sentinel-5, the objective of the mission is to reduce the gap in operational atmospheric chemistry data to be provided to the services from low earth orbit, continuing the datasets provided by GOME, SCIAMACHY, GOME-2 and OMI. The launch is foreseen in 2015 with a nominal lifetime of 7 years. As compared to the previous missions, the focus of S5p shifts towards air quality, which will be achieved through the unprecedented horizontal resolution, while at the same time continuing support to the climate and ozone layer investigations and services. The mission is developed in cooperation with the Dutch space agency and will be flown in loose formation with the NASA SNPP mission.

The single science payload carried by S5p is the nadir viewing TROPOMI instrument. It will provide daily coverage of earth radiance and reflectance data ranging from the UV-Visible (270-490 nm) to the near-infrared (710-775 nm), as well as the shortwave-infrared (2305-2385 nm) at high spectral and spatial (7x7km2) resolution. The calibrated Level 1b data will be provided to the user community. Due to the large size of the dataset the distribution details still need further specification.

The target trace gases that will be provided by the S5p mission are the column values for nitrogen dioxide, total and tropospheric ozone, sulfur dioxide, formaldehyde, carbon monoxide and methane, as well as the nadir ozone profile, aerosol and cloud information. The development of the operational products is based on existing experience and has been entrusted to the S5p Level 2 Working Group. All Level 2 data will be systematically provided to the services and user communities. The distribution mechanisms, which cover near real-time and offline services, are still under development.

The S5p products will need to be continuously monitored in order to ensure that data quality is in line with the performance requirements throughout the mission lifetime. For this purpose a dedicated team of experts will routinely assess the mission performance and monitor the data quality. These tasks include routine calibration, validation and quality control as well as the corrective and evolutive maintenance of processors and operational quality control tools. This will ensure an End-to-end system performance assessment.

This paper will provide an outline on the S5p mission products and their relation to the Copernicus/GMES Atmospheric Service Level 1b and Level 2 product requirements. An overview on the planned data dissemination, calibration/validation aspects as well as the foreseen mission performance functions will be presented.