Date of Award
3-2024
Document Type
Thesis
Degree Name
Master of Science in Applied Physics
Department
Department of Engineering Physics
First Advisor
Daniel J. Emmons, PhD
Abstract
Encompassing the Earth, the ionosphere presents unique challenges to modern communication, navigation, and surveillance technologies. Intense ionization enhancements known as sporadic-E (Es), can degrade and disrupt signals in unpredictable ways. Much work has been done to understand this phenomenon and more recent efforts have attempted to model its behavior and impacts. However, there have been limited efforts at modeling global Es occurrence rates (OR) at high time resolutions. This study develops a global empirical model of blanketing sporadic-E (fbEs) occurrence rates using a Karhunen-Lo´eve Expansion (KLE) of global fbEs OR climatologies built with Global Positioning System radio occultations (GPS-RO) and ionosonde soundings. At a 3 MHz threshold, the model outputs fbEs OR for a given geomagnetic latitude, longitude, day of year, and time of day. The model’s outputs were compared to Digisonde observations at four different locations with correlation coefficients ranging from 0.51 to 0.85 for monthly averaged observations and an uncertainty of 10.5% OR, while the average estimated uncertainty of the model is 8.8% OR. With the availability of COSMIC II data, new opportunities to develop higher resolution fbEs OR climatologies and consequently better models are emerging. A more extensive comparison of the model to more ionosonde locations would also provide greater confidence in the model’s performance.
AFIT Designator
AFIT-ENP-MS-24-M-047
Recommended Citation
Parsch, Eli V., "Global Empirical Model of Sporadic-E Occurrence Rates" (2024). Theses and Dissertations. 7692.
https://scholar.afit.edu/etd/7692
Comments
A 12-month embargo was observed for posting this work on AFIT Scholar.
Distribution Statement A, Approved for Public Release. PA case number on file.