V.E. Zakharov, D.C. Kotova

To describe the propagation of chirp signals in the ionosphere the numerical model is worked out. The propagation of short waves is considered. It is justified how every chirp signal to decompose into a sequence of the wave packets. The propagation of these wave packets in the non-uniform anisotropic ionosphere is modeled using the geometric optics approximation. To describe the parameters of ionosphere and of neutral atmosphere the experimental models IRI and MSIS are employed. The eikonal equation is integrated using characteristic approach to obtain the effective ray paths of the wave packets. Along an each of the ray paths the time delay, change of length, and attenuation of the wave packet is estimated. The model is developed to estimate the dispersive distortions of compound signals with a various band and an average frequency of spectrum in the ionosphere. It is taken into account that the wave packets with different values of average frequency propagate along different paths with different values of the group velocity. Newness of investigation is followed with taking the three dimensional non-uniformity and anisotropy of ionosphere to describe the propagation of compound signals in the ionosphere. The geomagnetic field is taken to be dipole. The effects of universal time are taken into account.