[time-nuts] GPS 1 PPS accuracy limits
SAIDJACK at aol.com
SAIDJACK at aol.com
Tue Apr 20 21:59:59 UTC 2010
Hi Magnus, Life speed,
what does accuracy mean? Average (rms, 1-Sigma) frequency accuracy? If yes,
over what time frame is the average?
Or is this the peak to peak allowable deviation? Over what temperature
range, and after how long of a warmup?
To give you an example, a typical Fury desktop unit with DOCXO is capable
of better than 2us holdover drift per day after 3 to 5 days of constant
operation.
That equates to an average frequency accuracy over one day without GPS of
<2.3 x 10^-11.
With GPS the accuracy on average is better than 2E-012 after about an hour
or so averaging.
bye,
Said
In a message dated 4/20/2010 13:07:53 Pacific Daylight Time,
magnus at rubidium.dyndns.org writes:
life speed wrote:
> Time Nuts;
>
> I have a customer request for a microwave frequency synthesizer with
extreme accuracy requirements;
> 4 X 10^-11, or 0.04 PPB. Obviously this is way out of quartz oscillator
territory.
> Is GPS 1 pulse-per-second useable, or do they need an atomic clock?
> Maybe they don't realize what they are spec'ing.
I really think you should ask them to motivate themselves on that spec,
the intended use etc. They can certainly get a spec like that, but is it
what they need?
You certainly want something like a GPS clock to feed that thing if they
really need that level of accuracy. Or do they only need that level of
resolution?
Cheers,
Magnus
More information about the Time-nuts_lists.febo.com
mailing list