This server also provides a GPS controlled NTP service.
A representation of the GPS constellation as visualised from the GPS receiver is shown below.

Software error:

Cannot connect to GPSClock port at univac.localdomain at /usr/local/www/cgi-bin/GPSmap.cgi line 60.

For help, please send mail to the webmaster (www@elkins.me.uk), giving this error message and the time and date of the error.

Software error:

[Sat Apr 18 08:20:11 2026] GPSmap.cgi: Cannot connect to GPSClock port at univac.localdomain at /usr/local/www/cgi-bin/GPSmap.cgi line 60.

For help, please send mail to the webmaster (www@elkins.me.uk), giving this error message and the time and date of the error.

The GPS receiver used is a Garmin GPS18xLVC: this is a straight forward unit, 12-channels, with WAAS capability, and of course PPS output, also noted for its sensitive receiver.
The GPS receiver positioning isn't perfect, as can be seen from the chart below, (it's actually located within the roof space) but this does not unduly degrade the system as a timekeeper, since it is able to rely on other NTP servers available via the net to provide synchronisation when the GPS system cannot do so (which is rare).
The GPS Clock 200, which used to be here, is now connected to another machine.

From the GPS receiver viewpoint, these are the tracks taken by the satellites, with the colours giving an indication of signal strength.
It's possible to make out certain obstructions near to the horizon, such as the house roof to the north. The effect of some large trees to the south is quite prominent due to the impact on signal strength, whilst the northern polar hole is clearly visible in the upper left/right quadrants.