Mathematical modeling of wave propagation in a non-stationary plasma in view of curvature of the Earth's surface and ionospheric layers

On a basis of the bi-characteristic system of equations in spherical system of coordinates the mathematical modeling of radiowave propagation of a decimeter range in a non-stationary ionosphere is executed in view of curvature of a surface of the Earth and ionospheric layers. The propagation of ordinary and extraordinary electromagnetic waves in conditions of fast formation of a sporadic layer is considered. The ray projections and component of a wave vector in spherical system of coordinates are constructed, the dependences of frequency of a signal on group time and latitude are investigated.