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.