Use of spectroradiometers

Light source and filter optimisation

Analysis of NVG compatibility usually starts with information generated by a spectroradiometer scan. This means tabulated data on either the output of a light source or the transmission of a filter material at defined wavelength intervals. This is produced for the wavebands covering the human eye response and the night vision goggle response, so 380nm to 930nm, usually at 5nm intervals.

This data then permits calculation of the characteristics of a light source in terms of the requirements of MIL-STD-3009 and other relevant specifications, including:

  • NVIS Radiance (the main measure of NVG compatibility)
  • Chromaticity (the colour of the light source, particularly important for aircraft cockpit instruments)
  • Luminance (how bright the source is)

Data for different sources and filters can be combined in modelling software to optimise performance before committing to manufacture.

Consolite has a number of spectroradiometers in its dark room facility and regularly designs and optimises filter and light source combinations, both for its own products and for its customers.