[ntp:questions] Leap second functional question

Greg Hennessy greg.hennessy at localhost.localdomain
Fri Feb 22 13:14:37 UTC 2008


On 2008-02-22, Unruh <unruh-spam at physics.ubc.ca> wrote:
>>I believe he is talking about the general relativity correction.  Even 
>>GPS would be wildly wrong if you used the earthbound definition of a 
>>second for the clocks in the satellites.
>
> A common misconception. The GPS people actually dynaically track the time
> delivered by the sattelites and adjust their scales accordingly.

It is not a misconception. The tweaks given to the clocks are much
less than the difference between pre launch and on orbit clock rates. 

>  Even if
> they know nothing of GR, they would have discovered that the clocks were
> running a bit fast and applied a correction fudgefactor.

This sounds like you are saying that even if they didn't know GR, they
would have discovered it. Which may in fact be true, but it doesn't
change the fact that GPS would be wrong if you used the sea level
definiton of a second from the on orbit clocks.




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