Patent ID: 8742978

Claim:
A method for determining signal propagation delay between a first station and a second station, comprising: generating a first series of first signal pulses in the first station at a first pulse-repetition rate f 1 ; generating a second series of second signal pulses in the second station at a second pulse-repetition rate f 2 and generating a third series of third signal pulses in the second station at a third pulse-repetition rate f 3 , with f 2 =f 1 +Δf and f 3 =f 1 −Δf applying to the pulse-repetition rates in the second station; transmitting, by the second station, the second series of second signal pulses and the third series of third signal pulses to the first station for receipt at the first station; feeding the second series of second signal pulses and the third series of third signal pulses received at the first station to a correlator and correlating the second series of second signal pulses and the third series of third signal pulses in the correlator with the first series of first signal pulses generated in the first station to generate a resultant series of result signal pulses; and determining the signal propagation delay from a time distance Δ between two successive signal pulses of the resultant series of resultant signal pulses.