Dual pilot frequency-correcting terminal stations for satellite repeater system

Claim 1

IN A COMMUNICATION NETWORK HAVING A PLURALITY OF GROUND BASED STATIONS, EACH INCLUDING A MULTIFREQUENCY CARRIER SOURCE, AND A SATELLITE REPEATER, THE IMPROVEMENT FOR AMELIORATING THE EFFECTS OF DOPPLER SHIFT COMPRISING: MEANS AT ONE GROUND BASED STATION FOR DERIVING FROM SAID MULTIFREQUENCY CARRIER SOURCE AND TRANSMITTING FROM SAID STATION AT LEAST TWO PILOT SIGNALS; MEANS AT EACH GROUND BASED STATION FOR RECEIVING AND EXTRACTING SAID PILOT SIGNALS; MEANS AT EACH GROUND BASED STATION SAVE SAID ONE FOR DERIVING FROM THE RESPECTIVE MULTIFREQUENCY CARRIER SOURCES AND TRANSMITTING FROM SAID STATIONS AT LEAST TWO LOCAL PILOT SIGNALS; MEANS AT EACH GROUND BASED STATION SAVE SAID ONE FOR RECEIVING AND EXTRACTING THE LOCAL PILOT SIGNALS TRANSMITTER THEREFROM THE LOOPED THROUGH SAID REPEATER; COMPARISON MEANS, AT EACH GROUND BASED STATION SAVE SAID ONE, COUPLED TO SAID PILOT SIGNAL RECEIVING AND EXTRACTING MEANS FOR DERIVING INFORMATION ON THE DOPPLER SHIFT OF SAID STATIONS''S SIGNAL; AND MEANS COUPLED BETWEEN SAID COMPARISON MEANS AND SAID MULTIFREQUENCY CARRIER SOURCE FOR VARYING THE OUTPUT THEREOF TO MINIMIZE THE VARIATION IN FREQUENCIES APPEARING AT THE SATELLITE REPEATER.