Satellite Instrumentation for the Measurement of Auroral Phenomenon

A variety of instruments have been employed aboard earth-orbiting polar satellites for measurements of the aurora phenomenon. Fixed-threshold total-energy detectors which utilize aluminum layers evaporated onto plastic scintillators for electron threshold determination in the 2-31 keV range and a photomultiplier operated in a constant current mode for viewing the scintillation light are described. A variable-energy detector which utilizes a programmed variable-energy threshold and post acceleration to detect electrons in the 80 eV to 1.6 keV energy range is also presented. The satellite data handling system for obtaining high spatial resolution is described.