Forrest Christian (List Account) wrote:
Depends on how synchronized you need to be.
Sure. But, we should be assuming NTP is mostly enough.
A rubidium oscillator or Chip Scale Atomic Clock is in the price range you quote. However, these can drift enough that you should occasionally synchronize with a reference time source. This is to ensure continued millisecond accuracy. Of course it all depends on how much drift you'll tolerate, and if you're OK with being within a second, then a rubidium might be ok.
For millisecond accuracy, Rb clocks do not need any synchronization for centuries. Rb clocks on GPS are a lot more frequently synchronized, because a lot more accuracy is required for positioning (10ns of timing error means 3m of positioning error). Masataka Ohta