Simulation of the Field in the Vicinity of Caustics of Ordinary and Extraordinary Waves during Ionospheric Propagation

The caustic structure of the electromagnetic field is mathematically modeled, when it appears near the ground surface during the decimeter radio wave propagation in the ionospheric plasma. The caustic structures of the fields of the ordinary and extraordinary waves are compared. The influence of the extraordinary wave on the amplitude structure of the ordinary wave field is also estimated in the vicinity of the caustic. The wave fields calculated with the help of the caustic approximation and with the help of the irregular ray approximation are compared. It is suggested to estimate the maximum value of the field amplitude in the vicinity of the caustic on the basis of the ray approximation.