The image of a monochromatic point source forms a distribution function centred at a given detector pixel. SWIR stray light is defined as light that hits the detector more than 3 spatial or more than 4 spectral pixels from the centre. The spectral stray light is monitored using the five on-board diode lasers. The amount of stray light is expressed both as a fraction of the laser light, as well as a detector map of the laser light. Measurements are taken monthly.
TROPOMI is a collaboration between Airbus Defence and Space Netherlands, KNMI, SRON and TNO, on behalf of NSO and ESA. Airbus Defence and Space Netherlands is the main contractor for the design, building and testing of the instrument. KNMI and SRON are the principal investigator institutes for the instrument. TROPOMI is funded by the following ministries of the Dutch government: the Ministry of Economic Affairs, the Ministry of Education, Culture and Science, and the Ministry of Infrastructure and the Environment.