Date of Award
2006
Degree Type
Thesis
Degree Name
Doctor of Philosophy
Program
Electrical and Computer Engineering
Supervisor
Dr. John W. MacDougall
Second Advisor
Dr. H. Gordon James
Third Advisor
Dr. Don Moorcroft
Abstract
Ionospheric tomography has developed in 20 years from a theoretical concept to a powerful e xperimental method and it has b een used s uccessfully t o image a wide range of ionospheric structures over altitude-versus-latitude planes. Measurements of the line integral of the electron density along ray paths from ground transmitter to satellite (i.e. TEC) are inverted in a reconstruction algorithm to create an image of the spatial distribution of the density over the region of interest. Recent ionospheric tomography experiments used VHF/UHF signals transmitted from NNSS or GPS satellite networks. We propose a new signal source transmitted from ground HF radars for the ionospheric tomography technique and the launch of the CASSIOPE satellite will provide an opportunity for this implementation. The thesis presents the methodology of the proposed HF tomography and proves the possibilities of its applications. The initial phase problem inherent in the phase or TEC measurement in the current ionospheric tomography using VHF/UHF signals and the ambiguity problem can be eliminated by using differential Faraday rotations. Resolution degradation due to ionospheric refraction effects on the HF signals of the reconstructed results can be solved by using a numerical ray-tracing method. In addition, other HF measurements such as: signal amplitude, group delay, direction of arrival and Doppler frequency shift can provide a priori information about the ionosphere. A scheme of transmitter arrangement in the CASSIOPEZe-POP satellite mission is proposed and a prototype HF dual-frequency transmitter is currently under testing.
Recommended Citation
Wang, Lan, "IONOSPHERIC TOMOGRAPHY IN THE CASSIOPE/E-POP SATELLITE MISSION" (2006). Digitized Theses. 4954.
https://ir.lib.uwo.ca/digitizedtheses/4954