[ntp:questions] NMEA ref.clock better than my ISP's timeserver?

Unruh unruh-spam at physics.ubc.ca
Thu May 28 16:40:01 UTC 2009

E-Mail Sent to this address will be added to the BlackLists <Null at BlackList.Griffin-Technologies.invalid> writes:

>Unruh wrote:
> > Note that my checking with something in germany is not going
> >  to give me very good timing. the earth is a large place.

>Isn't the round trip delay calc
>     (Client Destination TS - Client Origin TS)
>   - (Server Transmit TS - Server Receive TS)
>  diff supposed to help compensate for that?

jThe opperative words are "supposed to help". Yes, it helps. It does not
eliminate. It will eliminate ONLY if the one way times are identical.
They are not. They travel different paths across the surface of the
earth, they suffer different delays, etc. And the longer the path the
more of these differential delays there are. 

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