On the determination of ionospheric electron density profiles using multi-frequency riometry

Abstract. Radio wave absorption in the ionosphere is a function of electron density, collision frequency, radio polarisation, magnetic field and frequency. Several studies have used multi-frequency measurements cosmic noise to determine density profiles. Using framework statistical inverse problems, we investigated if an altitude profile can be determined by using multi-frequency, dual-polarisation measurements. It was found that cannot uniquely from “complete” measurement for all frequencies two polarisation modes. This implies accurate ascertained riometer data alone reconstruction requires strong additional priori assumption profile, such as parameterised model ionisation source. Nevertheless, spectral index could there significant component hard precipitation ionises lower part D region, but it not possible infer distribution with this technique alone.