Simulation of Doppler Frequency Shift in the Presence of Traveling Ionospheric Disturbances.

Mathematical modeling of the propagation of radio waves in the decameter range between the transmitter and receiver on inclined paths during the formation of traveling ionospheric disturbances (TID) has been carried out. The features of propagation when moving TIDs in both horizontal and vertical directions were studied. The characteristics of the radio channel: the group delay time of the radio signal, the Doppler frequency shift, the dependence of the ray exit angles on the position of the TID center at various frequencies and types of polarization of electromagnetic waves are calculated. It has been established that when the inhomogeneity moves horizontally, the center of the Doppler shift curve (zero value) move depending on the type of polarization of the radiation. The shape of the Doppler shift curve changes from a sinusoidal shape to a sawtooth with increasing frequency, the group delay curve has a minimum in the region of influence of the TID, and the region of influence of the disturbance itself significantly exceeds its characteristic size. With vertical movement, a three-ray region is formed, characterized by increased values of the Doppler frequency shift and group delay times. [ABSTRACT FROM AUTHOR]