The spatial extent of aurorae in O(5577) and Na2(4278) emissions

An investigation of the spatial extent of aurorae was undertaken from College, Alaska, by the ground based Lockheed two channel (5577 and 4278 Å) image intensifier TV system and with a multichannel boresighted tilting filter photometer. The measurements indicate that even on clear nights the extinction due to scattering in the 4278 Å is significant unless the measurements are taken at small zenith angles. To confirm the results and to avoid the low altitude scattering problem, measurements were made on a quite arc with the Lockheed 6 channel tilting filter zenith photometer during the NASA CV 990 expedition. These results show that in the cases observed there was no significant difference between the latitude profiles of O(5577) and N₂⁺(4278) emissions.