ROCKET-BORNE AIRGLOW PHOTOMETER.

This paper presents the design of a rocket-borne photometer to measure the airglow emission of ionized molecular nitrogen in the 391. 4 nm band. This airglow is a well-known and often observed phenomenon of auroras, where the principal source of ionization is energetic electrons. It is believed that at some midlatitude locations energetic electrons are also a source of nighttime ionization in the E region of the ionosphere. If this is so, then significant levels of 391. 4 nm airglow should be present. The intensity of this airglow will be measured in a rocket payload which also contains instrumentation to measure energetic electron differential flux and the ambient electron density. An intercomparison of the three experiments in a nighttime launch from Wallops Island will allow a test of the importance of energetic electrons as a nighttime source of ionization in the upper E region.