Assessment of Methods for Monitoring the Ionosphere by Observing UV and Visible Emissions

摘要

Two nighttime codes have been developed for obtaining the electron density profile in the lower to midlatiude ionosphere by using optical emission of oxygen 6300A and 1356A. The nighttime background present in the bandpass of a 6300A photometer was investigated. It was found that a 2A tilting filter photometer should be able to determine the true intensity of the oxgyen 6300A line within reasonable integration time constraints. A code was developed which determines limb intensity profiles for optically thick or thin emissions with or without pure absorption. The method is efficient and highly accurate. An analysis has been made of the data from a dayglow rocket experiment, UV intensities measured on board a sounding rocket, and ground based ionosonde data. The electron density profile and the UV intensities obtained from the data were compared with cooresponding results predicted by codes developed herein. It was found that the calculations could not reproduce both the electron density profile and the optical data, the discrepancy being, most pronounced at the lower altitudes. Keywords: Optical emissions; Satellite measurements; UV sensors; Electron density; Photometer; Rocket measurements; EUV emissions; Spectrometer; Dayglow; Nightglow; Photoelectron flux.