Validation of Bottom-Up GNSS Radio Occultation Method to Measure D- and E-Region Electron Density

Author

Dylan J. Shaver

Date of Award

3-2023

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Daniel J. Emmons, PhD

Abstract

An in-depth validation of a new bottom-up approach using GNSS Radio Occultation (GNSS-RO) data to generate electron density profiles in the D- and E-region ionosphere. This comparison was completed using daytime ionosonde profiles when sporadic-E (E_s) was not present, and corresponding FIRI profiles. The average GNSS-RO profile is a few kilometers higher in altitude than the ionosonde profiles at the minimum frequency, f min. When the ionosonde profiles are shifted so that the altitudes match at f min, they are in good agreement up to the E-region peak altitude, hmE. Below f min, the GNSS-RO profile is in good agreement with the FIRI profile, indicating that the profiles are able to measure the D- to E- transition region. The frequency of the E-region peak, foE, was well correlated between the GNSS-RO and ionosonde profiles, however, the hmE correlation was weaker and the GNSS-RO profiles tend to have an hmE in a narrow altitude range for all profiles. The bottom-up method performs well when compared against the shifted ionosonde profile, and does not show a clear latitudinal dependence on performance.

AFIT Designator

AFIT-ENP-MS-23-M-103

Comments

A 12-month embargo was observed.

Approved for public release. PA case number on file.

Recommended Citation

Shaver, Dylan J., "Validation of Bottom-Up GNSS Radio Occultation Method to Measure D- and E-Region Electron Density" (2023). Theses and Dissertations. 7353.
https://scholar.afit.edu/etd/7353