On Thu, October 18, 2007 14:21, Chuck said: > maybe that's why my offset on the pps kept drifting between -5 to +5 > microseconds. it seemed to do that about every 4 or 6 hours. maybe when it > switched to different satellites? or are gps geostationary? > > there are a lot of reasons, first of which this is an old motherboard i > did > the tests with. the cmos battery was dead.
> Chuck Your GPS is most probably speced with a PPS better than 1us. If you have decent satellite visability your PPS should be ok. The GPS is not switching satellites if you are not using a stationary timing mode. Does your Garmin have that mode? In normal modes you get time (and position) when you have 4 or more satellites in view. SBAS satellited (WAAS/EGNOS/MSAS) are GEOs. GPS is a MEO with 11.58h to do one lap around earth. Btw... have anyone done ntp-server experiments checking timing /NTP accuracy NOT using ntpd internal stats? -- Björn _______________________________________________ timekeepers mailing list [email protected] https://fortytwo.ch/mailman/cgi-bin/listinfo/timekeepers
