One of the major topics within the CEDAR program is the study of the mesosphere and lower thermosphere region of the atmosphere (80-110km). One technique used to study the structure and temperature of the region is to observe the intensity variation of particular emissions from constituents such as hydroxyl (OH) and molecular oxygen at night and during twilight. This award will allow the use of an existing high sensitivity infrared Michelson interferometer in various campaign activities located at different CEDAR stations covering low, middle and high latitudes. 3/3/89