The ATMOS (Atmospheric Trace MOlecule Spectroscopy) experiment - A tool for global monitoring of the middle atmosphere

A review is presented of the objectives, instrumentation, performance and results of the ATMOS program developed by NASA-JPL as part of the Spacelab 3 shuttle payload. ATMOS was developed to obtain high-resolution spectroscopic information of the middle atmosphere, from which the vertical distribution of the most possible trace and minor molecules could be retrieved. A complete occultation included not only data recorded when the optical path traversed the earth's atmosphere, but also many spectra with tangent heights big enough for no more telluric absorptions to be detected. The averaging of such 'high sun' observations has provided high quality solar spectra totally free of atmospheric absorption features.