Re: anyone running GPS clocks in Southeastern Georgia?

[Peter Lothberg <roll () Stupi SE>]

> On 1/21/11 2:26 PM, Robert E. Seastrom wrote:
> > Michael Holstein <michael.holstein () csuohio edu> writes:
> >
> > > > I'd be curious to see what effects (if any) those who use
> > > > GPS-disciplined NTP references in Southeastern Georgia see from this
> > > > experiment.
> > >
> > > Aren't CDMA BTS clocked off GPS?
> > >
> > > NTP isn't going to be the only "ripple".
> >
> > Sure, and there are GPS-steered Rb clocks in telco-land too as well as
> > a ton of stuff I don't know about yet until everyone else here chimes
> > in; it's just that NTP is highly visible to NANOGers.
>
> if your high quality stratum one time source isn't capable of
> free-running for a little while then it's not really high quality...
>
> you can of course test this simply by disconnecting the antenna. if the
> dilution of precision gets sufficiently high or the boise floor climbs
> above the signal then it should fail the gps out of the mix. our
> symerticoms have upgraded ocxo and backup geographically distant ntp
> sources in the pool to account for localized gps failure...
>
> I'm way to cheap to spring for the rubidum upgrade, the ocxo holdover is
> supposed to be 1ms a day.

The recomndation for a UTC timescales is to be within less than 1us of
UTC at any given time. 

-P