Campbell J W
Appl Opt. 1971 Jun 1;10(6):1254-62. doi: 10.1364/AO.10.001254.
A description is given of a rugged compact twin-channel stellar photometer developed for low resolution observations of stars in the wavelength region 1400-3000 A. The photometer employs two parallel Newtonian telescopes of large collecting area and incorporates photoelectric detection. Various methods of nondispersive wavelength isolation are described including what may be regarded as the state of the art in reflectance filter technology. The instrument has been successfully flown on six separate occasions under the auspices of the European Space Research Organization's program of collaborative research and yielded what are believed to be the first photoelectric stellar observations in Europe from above the earth's atmosphere.
