Multifrequency Scintillation in the Polar Caps

• Main Author: Colby, Tate
• Other Authors: 2410791
• Format: Text
• Language: unknown
• Published: Scholarly Commons 2022
• Subjects: Scintillation; Polar cap; Ionosphere; Plasma density; CERTO; CHAIN; RISR; Other Astrophysics and Astronomy; Arctic; Canada; Resolute Bay; Canadian High Arctic Ionospheric Network
• Online Access: https://commons.erau.edu/edt/691; https://commons.erau.edu/context/edt/article/1721/viewcontent/ColbyT_Thesis_signed.pdf

In the ionosphere, plasma density structures with scales sizes ranging from a few centimeters to hundreds of kilometers are capable of modifying the phase and amplitude of a radio signal in a rapid random manner in a process called scintillation. The Coherent Electromagnetic Radio Tomography (CERTO) and the Canadian High Arctic Ionospheric Network (CHAIN) are two different networks of scintillation receivers, each with a station in Resolute Bay, Canada. CERTO measures amplitude and phase signals in VHF and UHF while CHAIN measures amplitude and phase signals in the L-band. Through these measurements we can calculate the scintillation indexes, S_4 and sigma_phi to gain insight into the plasma density structures the scintillation originated from. In this Thesis, the processes of detrending and processing VHF sigma_phi from CERTO data and L-band S_4 & sigma_phi CHAIN data are detailed and the resulting scintillation data are analyzed by comparing the time of events to data from the Resolute Bay Incoherent Scatter Radar (RISR), creating histograms of the total scintillation data acquired, and by examining CERTO sigma_phi data results with respect to elevation angle. This work concludes that detrending scintillation data at frequencies other than L-band is not a trivial process and must be given care in order to produce accurate results. Within this work none of the RISR data contained significant plasma density during any of the satellite conjunctions analyzed. The histograms of total VHF and L-band sigma_phi values show more variation in the average VHF sigma_phi values than in the L-band sigma_phi. A positive correlation between the satellites elevation angle and increase in sigma_phi is identified.