Investigation of ionospheric O+ remote sensing using the 834-Å airglow


  • J. M. Picone,

  • R. R. Meier,

  • O. A. Kelley,

  • K. F. Dymond,

  • R. J. Thomas,

  • D. J. Melendez-Alvira,

  • R. P. McCoy


We have studied the feasibility of ionospheric O+ remote sensing through measurements of the 834-Å airglow. Our approach uses discrete inverse theory (DIT) to retrieve O+ number density profiles from the airglow. Our tests of this method assume observations by a limb-scanning system on an orbiting satellite at an altitude of 850 km. The scans cover the range of 10°–26.5° below horizontal, consistent with future multiyear missions. To provide a baseline assessment, we represent the synthetic ground truth (“true”) O+ distribution as a generalized Chapman-type profile with three or more parameters, based on our recent analysis of topside incoherent scattering radar data and standard ionospheric models (International Reference Ionosphere 1990 (IRI-90) and the parameterized ionospheric model (PIM)). The DIT method proves to be robust, converging to an accurate solution for a wide variation in ionospheric profiles. Using a detailed statistical error analysis of synthetic limb intensity data derived from the IRI-90 and PIM models, we work a difficult test case following from recent comments on the concept of 834–Å remote sensing of ionospheric O+. We find that the DIT method can correctly distinguish between distinctly different F layers that produce nearly identical intensity profiles, consistent with instrument specifications for future missions.