Application of the Nudged Elastic Band Method to Ionospheric Ray Tracing

Modeling the propagation of high-frequency radar signals via ray tracing is an important tool for quantifying ionospheric parameters associated with experimental data. The most common process modeling these paths is to use the method known as "homing." Recent research indicates that an alternative ray-tracing approach, using the Nudged Elastic Band (NEB) minimization method, yields more reliable results in cases of a highly perturbed ionosphere. In this investigation, a program using the NEB method for nuclear fission calculations was modified for use in ionospheric ray tracing. The resulting program models the ray path as a series of discrete points connected by springs. This pathway is then iteratively 'nudged' from an initial guess into the correct path, defined in this application by Fermat's Principle. We present convergent results by testing the algorithm's accuracy using a simple quasi-parabolic ionospheric model with existing analytic solutions. Future work will compare this program's performance with other ray-tracing methods and apply it to observations from Coastal Ocean Dynamics and Applications Radars.