This paper proposes a ray-tracing method to estimate a propagation path between a ground station and low-Earth-orbit (LEO) satellites. To accurately predict a propagation path and detection error, the proposed ray-tracing method adopts an atmospheric refractivity model that includes not only the troposphere but also the ionosphere. Herein, atmospheric refractivity in the troposphere is the measurement data obtained from weather observatories in Korea. In addition, atmospheric refractivity in the ionosphere is obtained from the simplified Appleton-Hartree equation. The detection angle errors are examined by changing various conditions, such as the locations of ground stations, satellite trajectories, and observation date. For the trajectories of the KOMPSAT-5 satellite, the maximum detection angle errors observed at inland and coastal meteorological observatories are 309 mdeg and 331 mdeg, respectively. The results demonstrate that the proposed ray-tracing method is suitable for determining the propagation path between the ground station and LEO satellites.



Keywords : Atmospheric modeling, Satellites, Refractive index, Low earth orbit satellites, Ray tracing, Radar tracking, Spaceborne radar, Atmospheric waves, Ionosphere, Mathematical models