Propagation From Geostationary Orbit Satellite to Ground Station Considering Dispersive and Inhomogeneous Atmospheric Environments

Abstract

We propose a novel method to calculate the propagation from a geostationary orbit (GEO) satellite to a ground station considering dispersive and inhomogeneous atmospheric environments with an actual satellite parabolic reflector antenna. The proposed simulation method is based on the hybrid numerical techniques including physical optics (PO), the 3-dimensional (3-D) ray tracing technique, and geometrical optics (GO). The electromagnetic propagation from an actual GEO satellite parabolic reflector antenna to a ground station at Seoul, Korea is calculated using PO. Reflections and refractions at the boundaries of the stratified refractive index model for the atmosphere are then calculated by the ray tracing approach and GO to take into account inhomogeneous atmospheric environments. Our method is verified by comparing with the results with the prediction method of rain attenuation given in ITU-R P.618-13 and the unified model. The comparison generally shows a good agreement. Atmospheric attenuation and boresight errors from a GEO satellite to a ground station are calculated and discussed. As a result of the calculations, when the rainfall rate is 26.19 mm/h, the atmospheric attenuation from a GEO satellite (COMS-1) to a ground station at Seoul, Korea is 12.1621 dB and the boresight error is 0.0336 degrees. INDEX TERMS Atmospheric environments, 3-D ray tracing technique, geometrical optics, physical optics, dispersive and inhomogeneous media.

Electromagnetic Wave Propagation From Low-Earth Orbit Satellite to Ground Station Considering Interpolated Atmospheric Environments

“…An effective refractive index neff in the troposphere and stratosphere can be calculated from the complex refractivity N via (2) where N`and N" are real and imaginary values of N [17]. In the ionosphere (i.e., cold/magnetized plasmas), the effective refractive index can be calculated by using Appleton-Hartree equation.…”

“…The effective refractive index neff in the ionosphere is calculated from electron density Ne, electron charge e, electron mass m, permittivity of free space, and angular frequency ω. Then, propagation constant γ and the effective intrinsic impedance ηeff can be calculated by ( 4) and ( 5) [17].…”

“…Every iteration decreases the maximum error halved, making the rapid convergence of the zenith and azimuth angles. One can refer to [17] for more details about the ray tracing technique applied here. If the ray path is fixed, the EM field is calculated at the boundary of the stratified layer.…”

“…However, to our knowledge, theoretical analyses for the EM wave propagation from a LEO satellite to a ground station are still lacking. In our previous work, we have shown a new approach to analyze the EM wave propagation in a well-defined single radio link, which is from a geostationary orbit (GEO) to a ground station, using high frequency approximation such as geometric optics (GO), ray tracing technique, and physical optics (PO) [17]. Unlike GEO satellites, LEO satellites orbit Earth much faster, approximately more than 12 times a day, such that the radio links can be significantly affected by atmospheric effects.…”