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Re-entry 23rd July 2006 01:18

UTC vs GPS
 
OK. Since the inception of atomic (caesium) clocks in the 1950's , we got UTC to replace proper GMT. I know in 1967. So when I am half way across the drink setting my watch, is it really UTC or what is it?

FarWest 23rd July 2006 03:44

  • UTC, Coordinated Universal Time, popularly known as GMT (Greenwich Mean Time), or Zulu time. Local time differs from UTC by the number of hours of your timezone.
  • GPS, Global Positioning System time, is the atomic time scale implemented by the atomic clocks in the GPS ground control stations and the GPS satellites themselves. GPS time was zero at 0h 6-Jan-1980 and since it is not perturbed by leap seconds GPS is now ahead of UTC by 14 seconds.
  • Loran-C, Long Range Navigation time, is an atomic time scale implemented by the atomic clocks in Loran-C chain transmitter sites. Loran time was zero at 0h 1-Jan-1958 and since it is not perturbed by leap seconds it is now ahead of UTC by 23 seconds.
  • TAI, Temps Atomique International, is the international atomic time scale based on a continuous counting of the SI second. TAI is currently ahead of UTC by 33 seconds.


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