Photometers
AEPI
The objective of the Atmospheric Emissions Photometric Imaging (AEPI) experiment was the investigation of the upper atmosphere-ionosphere and the space shuttle environment. The AEPI experiment was flown on the Space Shuttle as part of the Atmospheric Laboratory for Applications and Science (ATLAS 1). The goals of this experiment were (1) investigation of ionospheric transport processes by observing positive magnesium (Mg) ions, (2) studies of optical properties of artificially induced electron beams, (3) measurement of electron cross sections for selected atmospheric species, (4) studies of natural airglow, and (5) studies of natural auroras. Many experiments were performed with the AEPI instrument in coordination with other ATLAS 1 instruments (ISO and SEPAC). The experiment also investigated optical emissions generated by the Shuttle. The equipment consists of (1) a dual-channel low-light-level television (LLLTV) system, photon counting array and associated electronics, (2) a low-light-level unfiltered (spectral continuum) TV camera which consists of an Augeniux 50 mm f/0.95 lens focused at infinity whereby an image is formed on a single-stage microchannel plate intensified inverter tube coupled to an uncooled CCD via a fiberoptic taper, (3) dedicated experiment processor (DEP) which controls the detector functions including filter wheel positioning, camera focusing, prism movement, intensifier gain control, and gain control, (4) a small hand-held image intensifier and associated filters and manually operated spectrometer which can be used by the payload crew to monitor low-light-level phenomena, and (5) a video data encoder (VDE) for annotating video with essential housekeeping and experiment parameters. The magnesium positive ion resonance line is imaged at 279.5 and 280.2 nm and the 2p state singly ionized atomic oxygen is obtained at 731.9 and 247.0 nm. Further information about the ATLAS-1 mission can be found at: "http://wwwghcc.msfc.nasa.gov/atlas1.html" IDN_Node: USA/NASA