Ray tracing applications for high-frequency radar: characterizing artificial layers and background density perturbations in the ionosphere

Abstract

In this thesis a numerical method of calculating ground-scattered power from the results of a ray tracing analysis is presented. The method is based on a conservation of energy approach and offers advantages over an alternative method derived from the radar equation. The improved numerical method is used to investigate two different physical phenomena by comparison with measured ground-scattered power observed by a high-frequency (HF) radar located in Kodiak, AK that is part of the Super Dual Auroral Radar Network (SuperDARN). First, the effects of artificial electron density layers on observed ground scatter is studied through a comparison of simulated and measured power profiles. The results demonstrate that the location and spatial dimensions of artificial layers may be estimated by a comparison of the location and amplitude of simulated and measured power enhancements. Second, a Monte-Carlo simulation method is used to characterize the temporal distribution of ground-scattered power. Random processes including background electron density perturbations, polarization, noise, and sample correlation are modeled in simulation and used to estimate statistical moment profiles. The simulated statistical moment profiles are compared to measured profiles as a means of model verification and to roughly approximate background electron density perturbations in the ionosphere.