An application of the Michelson interferometer to nonthermalized spectral features in the night airglow

An application of the Michelson interferometer is described which extends its use into areas where high resolution measurements of dim sources are required but only part of the total spectral information is needed. The instrument is described in a form which was developed to facilitate the estimation of the ratio of intensities of components in a two component composite line profile. The technique also provides directly an approximate correction for contamination of the results due to unmodulated continuum.