Satellite-ground frequency difference calibration method and system for geostationary orbit satellite communication system by adopting GBBF technology

The invention provides a satellite-ground frequency difference calibration method and system for a geostationary orbit satellite communication system by adopting a GBBF technology. The method comprises the following steps: 1) sending a pilot signal on the ground; 2) receiving the pilot signal by a satellite, carrying out frequency conversion forwarding on the pilot signal, and looping back to theground; when the satellite forwards the loopback pilot signal, sending two paths of pilot signals with different frequencies to ground; 3) the ground receiving the loopback pilot signals and the pilotsignals and calculating the center frequency of the three paths of pilot signals; calculating a satellite-ground motion Doppler factor K and an upper planet ground medium Doppler frequency offset; 4)adjusting the intermediate frequency of the n feed source signals by the ground surface, and compensating the frequency difference between the feed sources during spatial transmission of the feed sources; (5) up-converting the