AUTOMATED GROUND-BASED STAR-POINTING UV-VISIBLE SPECTROMETER FOR STRATOSPHERIC MEASUREMENTS

A novel automated ground-based star-pointing spectrometer system has b een constructed for long-term deployment in Antarctica. Similar to our earlier stellar system, a two-dimensional detector array measures the spectra of the star and the adjacent sky, so that auroral emission fr om the sky can be subtracted from the stellar signal. Some new feature s are an altitude-azimuth pointing mirror, so that the spectrometer do es not move; slip rings to provide its power thereby avoiding flexing of cables and restriction of all-around viewing; and a glazed enclosur e around the mirror to ensure protection from rain and snow, made from flat plates to avoid changing the focal length of the telescope. The optical system can also view sunlight scattered from the zenith sky. T he system automatically points and tracks selected stars and switches to other views on command. The system is now installed at Halley in An tarctica, and some preliminary measurements of ozone from Antarctica a re shown. (C) 1997 Optical Society of America.