A compact low-radiance multichannel reference source of diffuse visible and near-infrared radiation for airglow studies

A description is given of a reference light source constructed for use with a three-channel airglow spectrometer. It uses the principle of the integrating sphere, to meet the requirements of compactness and portability, supplying approximately white light of low and uniform radiance and of selected intensity into each of three apertures of diameter about 100 mm.