A Method for Automatic Scaling of Ionograms and Electron Density Reconstruction

Abstract

Ionogram scaling is the process of reconstructing electron density with respect to height by using the measurements of a remote sensing instrument known as ionosonde. In this study, a novel two stage ionogram scaling technique, ISED, is proposed. In the first stage, Hidden Markov Models (HMMs) are used to identify the actual ionospheric reflections in the ionosonde measurements. In the second stage, an IRI-Plas model based optimization problem is solved to obtain the vertical profile that generates the best least squares fit to the reflections identified in the first stage. To show the performance of ISED in global scale, experiments are conducted on 14,812 ionograms recorded at the three different stations which are Pruhonice in Czech Republic, Eielson in USA and Sao Luis in Brazil. Application of ISED to raw ionograms indicate 97.6% of the cases, ISED provides accurate electron density reconstructions, which is an improvement about 8.7% over ARTIST, most commonly used ionogram scaling technique.

IONOLAB-Fusion: Fusion of Radio Occultation into Computerized Ionospheric Tomography

“…As shown in Figure 14, the electron density that was reconstructed with IONOLAB-Fusion using the IRI-Plas model aligned better with the ionosonde vertical profiles up to hmF2. However, at higher altitudes, which is known as the topside, differences in the underlying models between the IONOLAB-Fusion and ionosonde inversion algorithms led to discrepancies between the reconstructed electron density values and ionosonde vertical electron density profiles [73]. This was especially the case beyond the Chapman height, where notable disparities emerged between the ionosonde vertical electron profiles and the reconstructed electron density profiles that were constructed by IRI-Plas.…”

An Improved Method for the Inversion of Backscatter Ionograms by Using Neighborhood-Aided and Multistep Fitting

“…Studying the characteristics of ionospheric media is one of the most important areas of ionospheric scientific research and geospatial environment monitoring [1]. This subject is closely related to frequency selection and equipment deployment in modern radar, communication and navigation systems [2].…”