Ground-wave propagation. Part 1: Theory for short distances

Ground-wave propagation over a curved earth with a troposphere whose refractive index varies with height is considered. Series expansions are derived whose first term is the Sommerfeld flat-earth formula. These expansions generalise previous results by the inclusion of the effects of the inhomogeneous refractive-index variation. The methods described are induded in the ground-wave-propagation program GRWAVE.