An evaluation of a new two-dimensional analytic ionospheric ray-tracing technique: Segmented method for analytic ray tracing (SMART)

Analytic ray tracing is considerably less time consuming than numerical ray tracing. However, despite the advantage of speed, analytic ray tracing has a major limitation: the difficulty of including the effects on the ray pat h of horizontal gradients in electron density. In the past this difficulty has been addressed using ionospheric models whereby an effective tilt is in troduced by displacing the center of the ionosphere from the center of the Earth. In this paper, ray equations for the ground range, phase path, group path, and divergent power loss are developed for a new two-dimensional ana lytic ray tracing technique,known as the segmented method for analytic ray tracing (SMART), which is able to deal with horizontal gradients in electro n density. Ray tracing using two tilting methods are compared with ray trac ing using SMART. Further, these results are compared with a numerical ray t racing program known as homing-in ray tracing (HIRT).