Auroral photometers aboard the Aureol-3 satellite - The ALTAIR experiment

The Altair experiment has been designed for the conduction of measurements of the main emissions of the upper atmosphere. The emissions are produced in connection with excitations due to auroral electrons and protons along the dark portions of the orbit of the Aureol-3, which carries the Altair experiment. The equipment used for the conduction of the measurements includes four photometers. Three auroral photometers with parallel optical axes are directed toward the earth at an angle of 20 deg from the nominal nadir. A fourth photometer is employed as a stellar sensor for a more precise determination of the satellite attitude in dark portions of the orbit. A description of instrumental details is provided, and aspects of inflight operation are discussed.