Question

GPS satellites orbit the earth with a speed of 14000 km/hr relative to fixed positions on earth. Is this a relativistic speed? By how much do clocks on the satellites lag behind clocks on earth per day? If the timing of signals from the satellites received by an earth receiver must have 20 ns precision to determine position within 5 meters, can special relativity be ignored? How long before the difference in time measurements would exceed the required precision?

Answer 1