OBLIQUE SOUNDING IONOGRAM SIMULATION BY THE GENERALIZED FORCE METHOD

An implementation of the generalized force method, which is best suited for ray tracing in an anisotropic ionosphere with given positions of the transmitter and receiver, is presented. The ray search is based on the optimization of the extended functional of the phase path, taking into account both the spatial position of the ray and the direction of the wave front. Note that, regardless of the chosen mode configuration, the optimization problem, as in the isotropic case, comes down to determining the set of extrema of the objective function: as a rule, minima for the high rays and saddle points for the low rays. The generalized force method, implemented as a software model, has been tested and applied to solve oblique sounding problems in a realistic ionosphere using the NeQuick2 and IGRF13 models.