Validation of nighttime UV measurements of the F region ionosphere made by the low resolution airglow and aurora spectrograph (LORAAS) instrument

Abstract

We present electron density profiles derived by inversion of ultraviolet limb radiances observed during November 2000 through April 2001 by the low resolution airglow and aurora spectrograph (LORAAS) instrument on the Advanced Research and Global Observing Satellite (ARGOS). The O+ density profile, which is approximately equal to the electron density profile in the F region ionosphere, was determined by inverting the limb radiance profile of O I 1356 Å emission of atomic oxygen; the 1356 Å emission is produced purely by radiative recombination of O+ ions and electrons at night and has been shown to be a viable means of globally sensing the ionospheric state. Dymond et al. (2001b) showed a preliminary validation of this technique covering a single day of observations. We have performed a more extended validation of the retrieved peak electron density and peak height determined by inversion of nighttime observations of the 1356 Å altitude profiles with coincident ionosonde measurements and climatology.