1. Pre-launch calibration results of the TROPOMI payload on-board the Sentinel 5 Precursor satellite.
- Author
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Kleipool, Quintus, Ludewig, Antje, Babic, Ljubiša, Bartstra, Rolf, Braak, Remco, Dierssen, Werner, Dewitte, Pieter-Jan, Kenter, Pepijn, Landzaat, Robin, Leloux, Jonatan, Loots, Erwin, Meijering, Peter, van der Plas, Emiel, Rozemeijer, Nico, Schepers, Dinand, Schiavini, Daniel, Smeets, Joost, Vacanti, Giuseppe, Vonk, Frank, and Veefkind, Pepijn
- Subjects
TROPOSPHERIC chemistry ,GEOGRAPHIC spatial analysis ,GEOSTATIONARY satellites - Abstract
The Sentinel 5 precursor satellite was successfully launched on 13th October 2017, carrying the Tropospheric Monitoring Instrument TROPOMI as its single payload. TROPOMI is the next generation atmospheric sounding instrument, continuing the successes of GOME, SCIAMACHY, OMI and OMPs, with higher spatial resolution, improved sensitivity and extended wavelength range. The instrument contains four spectrometers, divided over two modules sharing a common telescope, measuring the ultraviolet, visible, near-infrared and shortwave infrared reflectance of the Earth. The imaging system enables daily global coverage using a push-broom configuration, with a spatial resolution as low as 7×3.5km
2 in nadir from a Sun-synchronous orbit at 824km and an equator crossing time of 13:30 local solar time. This article reports the pre-launch calibration status of the TROPOMI payload as derived from the on-ground calibration effort. Stringent requirements are imposed on the quality of on-ground calibration in order to match the high sensitivity of the instrument. In case that the systematic errors that originate from the calibration exceed the random errors in the observations, the scientific products may be compromised. A new methodology has been employed during the analysis of the obtained calibration measurements to ensure the consistency and validity of the calibration. This was achieved by using the production grade Level 0 to 1b data processor in a closed-loop validation setup. Using this approach the consistency between the calibration and the L1b product could be established, as well as confidence in the obtained calibration result. This article introduces this novel calibration approach, and describes all relevant calibrated instrument properties as they were derived before launch of the mission. For most of the relevant properties compliancy with the requirements could be established, including the knowledge of the instrument spectral and spatial response functions, and the absolute radiometric calibration. Partial compliancy was established for the straylight correction; especially the out-of-spectral-band correction for the NIR channel needs further validation. Incompliance was reported for the relative radiometric calibration of the Sun port diffusers. These latter two subjects will be addressed during the in-flight commissioning phase in the first 6 months following launch. [ABSTRACT FROM AUTHOR]- Published
- 2018
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