DETERMINATION OF VIBRATIONAL POPULATION DISTRIBUTION FOR THE ${N_2}^{+}$ (1N) ION BAND SYSTEM FROM SPACELAB 1

The Spacelab 1 data represented the first multiband spectral measuremets of the ${N_2}^{+}$ first negative ion bands system in the thermospheric dayglow, and the first opportunity to make a detailed comparison of the vibrational and rotational distributions over bands out to v'=5. The main purpose of this study was to decuced the excitation processes of ${N_2}^{+}$(1N) bands by determining vibrational population distributions for the upper states of ${N_2}^{+}$(1N). The vibrational population distributions to achieve a best fit to the measured Spacelab 1 data were summarized and also compared with those theoretically derived.