On Geometric Optics Over a Spherical Earth With an Exponential Refraction Index

The ray-based method of geometrical optics can be used for wave propagation over a spherical earth with good results. A previous such a method also includes an exponential refraction index. This method gives good results for large terminal heights and distances, but for small distances, it has some shortcomings. In this paper, an improvement is proposed which removes these shortcomings. Also, as the method depends on numerical procedures, some improved numerical calculations are put forward.