[ntp:questions] NMEA-PPS and the lost "1 second"

Terje Mathisen terje.mathisen at hda.hydro.com
Fri Apr 27 19:11:14 UTC 2007

David Anullo wrote:
> I, finally (for those that have read my precedent question), make a 
> gps-pps-nmea test. But now i have see that when gps lost the satellites 
> signal (remain with 3-4 good satellites), the offset (i have plot the 
> peerstat file) goes down immediately to 1 second.
> Until that the satellites are "down" the offset-trend seems that it 
> tries to recover slowly this large gap. When they re-enter the offset 
> returns to the values of the normal trend (approximately one straight 
> line therefore..).
> I understand that without satellite's signal the time precision is not 
> guaranteed but don't understand why i always see this "1-second" gap..

This sounds like a dropped signal, either PPS or serial.


- <Terje.Mathisen at hda.hydro.com>
"almost all programming can be viewed as an exercise in caching"

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