Radio Propagation Through Density Irregularities in the Auroral Ionosphere
A radio wave propagating through a structured or turbulent ionosphere undergoes multiple effects, such as refraction, diffraction, etc., that distort the incident radio wave by inducing phase and amplitude fluctuations. These fluctuations are called ionospheric scintillation. Scintillation effects c...
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Text |
| Language: | unknown |
| Published: |
Scholarly Commons
2024
|
| Subjects: | |
| Online Access: | https://commons.erau.edu/edt/841 https://commons.erau.edu/context/edt/article/1871/viewcontent/Dissertation_PV_signed_all.pdf |
| Summary: | A radio wave propagating through a structured or turbulent ionosphere undergoes multiple effects, such as refraction, diffraction, etc., that distort the incident radio wave by inducing phase and amplitude fluctuations. These fluctuations are called ionospheric scintillation. Scintillation effects can be detrimental to Global Navigation Satellite Systems (GNSS) such as Global Positioning System (GPS), but the observed effects can be used as a tool to study the underlying plasma process that causes scintillation. Scintillation is commonly seen in equatorial and high-latitude regions. This study centers around the scintillation and its causative plasma processes that dominantly happen in the high-latitude ionosphere over the auroral regions (or the auroral ionosphere where we see northern and southern lights). The aim of this dissertation is to investigate the impact of ionospheric density irregularities on radio wave propagation by studying their characteristic features and ionosphere conditions during radio scintillation. We employ a modeling approach using a radio wave 3D propagation model: Satellite-beacon Ionospheric-scintillation Global Model of the upper Atmosphere (SIGMA), interfaced with various plasma density models, including spectral models, namely Hybrid, Shkarofsky, stochastic model, Configuration Space Model (CSM), and plasma-based density model Geospace Environment Model of Ion-Neutral Interactions (GEMINI), to simulate the radio wave scintillation through ionospheric density irregularities. SIGMA simulates a GPS signal propagated through a phase screen from a moving satellite to the ground. The phase screen is the spatial electron number density distribution characterized using one of the density models that affect the phase of the forward propagating radio signal. We have examined and compared the irregularity morphology of E- vs. F-region density irregularities using SIGMA coupled with spectral models (Hybrid and Shkarofsky) and inputs from auxiliary measurements, such as Incoherent Scatter ... |
|---|