Method for simultaneous measurement of the frequency-amplitude characteristics and the Doppler frequency shift of a multipath short wave radio line

The paper shows the possibility of increasing the information content of measuring the amplitude-frequency response of a short-wave radio line by measuring the Doppler frequency shift of each mode. A method of such measurement is proposed based on a modified method of oblique sounding of the ionosphere with a linear frequency modulated signal. The technique is as follows: the first preliminary session of oblique sensing is conducted with a high frequency tuning rate (1000-5000 kHz/s) in order to obtain information about delays and amplitudes in a wide frequency range; next, the received ionogram at the receiving point is automatically processed in order to determine the zones of interest, the sensing parameters for subsequent ionograms are determined at a frequency tuning rate of 100-500 kHz/s – the step value between the initial frequencies of linearly frequency modulated pulses; the parameters of the reception session are set; then the sensing scheme for subsequent ionograms is transmitted from the receiving point to the transmitting point using on the Internet or by radio channel; subsequent long-term probing sessions are conducted; The Doppler shift at frequencies is calculated according to the scheme for subsequent ionograms, and the amplitude-frequency response of the radio line according to ionograms from all sensing sessions.