Oral Presentation

Simulation of Footprints of a Radar Beam at High-frequency Waves for Ionospheric Over-The-Horizon Communication

Author(s): De-Shao Yao, Yen-Hsyang Chu, Ching-Lun Su Graduate Institute of Space Science and Engineering, National Central University

Presenter: De-Shao Yao (Graduate Institute of Space Science and Engineering, National Central University)

Over the horizon (OTH) communication uses a ground-based high-frequency (HF) radar to transmit oblique HF electromagnetic wave (EM wave) into ionosphere and receives the radar echoes at a remote site, which are reflected by the ionosphere at a level with specific electron density. In this study, on the basis of the ray theory, we develop a numerical model to simulate the ionospheric sky wave propagation for OTH communication. The purpose of this study is to simulate the footprint of a radar beam that is obliquely transmitted and reflected by the ionosphere. The International Reference Ionosphere (IRI) model and International Geomagnetic Reference Field (IGRF) model are employed to construct the propagation channel for OTH propagation. The Adams-Bashforth-Moulton method is adopted in the numerical simulation to calculate the ray step. In addition to simulate ray paths of the ordinary wave (O-wave) and extraordinary wave (X-wave) for a linearly polarized radar ward, we also study the Faraday rotation effect on the polarization of a linear polarized EM wave during its propagation in the ionosphere. The simulation result indicates that the changes in the transmitted frequency, propagation path and geomagnetic filed strength will lead to the change in the coverages and configurations of the footprints of the O-wave and X-wave of the radar beam on the receiving site. In addition, the rotation angle of the polarization of the sky wave at the receiver end will also be changed accordingly.