[LEAPSECS] preprint about timekeeping for neutrino experiment

[Tom Van Baak]

>> And the clocks are not locked to a receiver, they are free but the offset

>> is continuously monitored through those CV measurement.

>

> Would you not lock the GPS (GNSS) receivers to the CS-clocks being compared?

>

> Björn


It's pretty common with high-performance timing to NOT lock the
local clock to GPS. There are several reasons for this. One is that
you get the both the best stability of the undisturbed local clock
plus a continuous log of the difference between the local clock
and the external timing source (GPS). Locking an oscillator to
GPS introduces its own set of noise. Locking implies real-time
processing of the GPS signal (you miss a lot of performance
that way).

The other reason is that they are at least using common view, if
not other forms of post-processing, to greatly improve accuracy.
There's always a trade-off between good GPS timing in real time
or superb GPS timing if you wait days or weeks and crunch all
the numbers.

/tvb