jp7dvx
October 10, 2026, 1:15pm
1
Hi everyone,
I wanted to share my recent setup of a Stratum 1 NTP server using GPS/QZSS as a reference source.
System Status & Performance:
Stratum: 1 (NMEA / PPS)Offset: ~0.1 ms (System time is ~0.000105 s slow of NTP time)Satellites: Tracking multiple GPS and QZSS (PRN 195, etc.) satellites via gpsd / xgps.
Attached are screenshots of chronyc tracking and xgps showing the signal reception and timing precision.
Hope this helps or inspires anyone looking to build a precise time reference for their ground station!
1 Like
PE0SAT
October 10, 2026, 1:46pm
2
Thanks for sharing, does you GPS receiver also provide PPS?
This will give you an even better time accuracy.
Reference ID : 50505300 (PPS)
Stratum : 1
Ref time (UTC) : Sat Oct 10 13:45:25 2026
System time : 0.000000104 seconds slow of NTP time
Last offset : -0.000000155 seconds
RMS offset : 0.000000661 seconds
Frequency : 12.186 ppm fast
Residual freq : -0.002 ppm
Skew : 0.041 ppm
Root delay : 0.000000001 seconds
Root dispersion : 0.000015167 seconds
Update interval : 8.0 seconds
Leap status : Normal
Jan | PE0SAT
2 Likes
jp7dvx
October 10, 2026, 10:00pm
3
Thanks! Since this is a USB dongle, I’m only using NMEA right now. PPS sounds great for even better accuracy—might look into it if I upgrade the hardware later.
1 Like
bali
October 16, 2026, 10:47am
4
sudo chronyc tracking
Reference ID : 50505300 (PPS)
Stratum : 1
Ref time (UTC) : Fri Oct 16 10:42:15 2026
System time : 0.000000052 seconds slow of NTP time
Last offset : -0.000000052 seconds
RMS offset : 0.000000948 seconds
Frequency : 17.424 ppm fast
Residual freq : +0.001 ppm
Skew : 0.098 ppm
Root delay : 0.000000001 seconds
Root dispersion : 0.000011520 seconds
Update interval : 16.0 seconds
Leap status : Normal
indicator: smaller RMS offset and Skew, better
1 Like
