[time] GPS Time Server Survey

Chris Kuethe chris.kuethe
Thu Apr 24 20:46:45 UTC 2008


On Thu, Apr 24, 2008 at 12:37 PM, Jan Hoevers <ml.janhoevers at xs4all.nl> wrote:
> Kipton Moravec wrote on 24-4-2008 18:14:
>
> > 1. A GPS module with the ability to expand the serial port to more than
>  > 10 to allow you to use the NTP NEMA driver. The time pulse would be
>  > accurate to about 30 nS RMS. Retail cost about $100.
>  Quite unlikely, since the GPS system itself does not have 30 ns
>  accuracy.  That kind of accuracy is meaningless for pool server
>  operators anyhow.  They typically do not own cesium clocks and the
>  regular pc oscillator is not stable enough to maintain that kind of
>  accuracy.

Good chips aren't that hard to get. If the datasheets are to be believed:

Trimble Lassen iQ 	50ns
Trimble Resolution-T 	15ns
ublox Antaris4T 	50ns,15ns compensated
NavSync CW25-TIM 	25ns
SigNav TM3-01 	10ns
NavSync CW12-TIM 	30ns
Motorola OnCore UT+ 	50ns
Motorola/iLotus/Synergy-GPS M12M 	20ns, 6ns corrected

-- 
GDB has a 'break' feature; why doesn't it have 'fix' too?



More information about the pool mailing list