Variations of the trajectory characteristics of oblique-sounding signals under the conditions of the artificially disturbed ionosphere

The results of a solution of the direct and inverse problems of oblique sounding (OS) of an artificially disturbed region of the upper ionosphere are given. It is shown that such a region leads to significant changes in the group delay of 0S signals passing through, which can be used in the problem of remote diagnostics of a disturbance in electron density. According to the theory of resonance instability of the ionospheric plasma, during vertical action on the ionosphere of strong electromagnetic fields, a disturbance of the medium occursat the altitudes where the frequency of the strong radio emission coincides with the plasma frequency. The disturbed region is a large-scale formation and, depending on its altitude, can have a decreased or increased electron density relative to the background value [i]. Below we consider the influence of such a large-scale disturbed region, localized near the midpoint of the path, on the trajectories of waves of oblique sounding (OS) of the ionosphere passing through it, in a wide range of frequencies, and the possibility of remote diagnostics of a disturbance in electron density in a heated region Ss shown. The direct and inverse problems of oblique sounding of the two-dimensionally ionosphere were solved in the geometrical-optics approximation of radio-wave propagation. The trajectory of a ray in the nonuniform ionosphere is described by a system of vector equations [2]. For the simplified case of a two-dimensionally nonuniform, isotropic medium, possessing greater clarity of ~he mechanisms of refraction of a ray, the system of ray equations can be represented in the simpler form [3]