Up-down photometers for auroral profile studies.

An ultraviolet rocket-borne photometer system currently under development is described which alternately measures zenith and nadir intensities at rocket altitude. This configuration allows calculation of total vertical column intensity of the features observed, and therefore provides information useful in separating temporal and spatial variations in intensities recorded by other instruments with fixed, forward rocket orientations. When it is possible to observe a single spectral feature, calculation of the volume emission rate is possible from the data. Several configurations have been flown which monitor a blend of lambda2972 [OI] ((1)S?(3)) and lambda2977 N(2) second positive (2,0) band, and reference is made to the results. Plans for a system involving also lambda3159 N(2) second positive (1,0) band are described.