Articles | Volume 11, issue 7
Atmos. Meas. Tech., 11, 3917–3933, 2018

Special issue: TROPOMI on Sentinel-5 Precursor: data products and...

Atmos. Meas. Tech., 11, 3917–3933, 2018

Research article 04 Jul 2018

Research article | 04 Jul 2018

Determination of the TROPOMI-SWIR instrument spectral response function

Richard M. van Hees1, Paul J. J. Tol1, Sidney Cadot1,2, Matthijs Krijger1,3, Stefan T. Persijn5, Tim A. van Kempen1, Ralph Snel1,4, Ilse Aben1, and Ruud W. M. Hoogeveen1 Richard M. van Hees et al.
  • 1SRON Netherlands Institute for Space Research, Utrecht, the Netherlands
  • 2Jigsaw B.V., Delft, the Netherlands
  • 3Earth Space Solutions, Utrecht, the Netherlands
  • 4Science and Technology B.V., Delft, the Netherlands
  • 5VSL Dutch Metrology Institute, Delft, the Netherlands

Abstract. The Tropospheric Monitoring Instrument (TROPOMI) is the single instrument on board the ESA Copernicus Sentinel-5 Precursor satellite. TROPOMI is a nadir-viewing imaging spectrometer with bands in the ultraviolet and visible, the near infrared and the shortwave infrared (SWIR). An accurate instrument spectral response function (ISRF) is required in the SWIR band where absorption lines of CO, methane and water vapor overlap. In this paper, we report on the determination of the TROPOMI-SWIR ISRF during an extensive on-ground calibration campaign. Measurements are taken with a monochromatic light source scanning the whole detector, using the spectrometer itself to determine the light intensity and wavelength. The accuracy of the resulting ISRF calibration key data is well within the requirement for trace-gas retrievals. Long-term in-flight monitoring of SWIR ISRF is achieved using five on-board diode lasers.