Estimating high-energy electron fluxes by intercalibrating Reimei optical and particle measurements using an ionospheric model

Abstract

This paper describes a technique for intercalibrating particle and optical measurements from the Reimei microsatellite using an ionospheric model. Reimei has three auroral cameras (“MAC”), together with electron and ion energy spectrum analysers (“ESA/ISA”). The maximum electron energy measured is 12keV, which means that during high-energy events, the particle data are often missing an important part of the energy flux. Although the total electron energy flux can be estimated from the optical measurements, the MAC data must be accurately calibrated, which is complicated by an unknown and variable background from sources such as the moon and snow reflection. Using unsaturated ESA measurements of the complete electron spectrum as input for an ionospheric model, the coincident camera observations can be calibrated, allowing estimates to be made of the total electron energy flux at other times during the same event, when the maximum energy is well above that measured by ESA.