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Serve as Stratum 1 NTP Server

Observer can share its internal time source through the NTP Server Service. Use this for trusted LAN clients when the Explorer has a verified GNSS time source.

Prepare the Station​

  1. Connect the Explorer and verify GNSS time availability in the dashboard. Allow the receiver to acquire a stable fix.
  2. Keep the NTP client pool in config.json configured for startup and fallback synchronization.
  3. Check that no existing NTP daemon is listening on UDP 123. On Linux, inspect sudo ss -lunp before enabling another server.
  4. If running as an unprivileged Linux user, grant CAP_NET_BIND_SERVICE through the service unit. The Observer installer already configures this capability.

The NTP server does not synchronize the host operating system clock. It serves Observer's own time source. Avoid creating a synchronization loop where the host and Observer rely on each other as their only reference.

Enable Serving​

In Settings → Service Modules → NTP Server, enable the service, select the intended LAN binding, and leave Listen Port at 123 for standard clients. Save and restart the module. Permit inbound UDP 123 from the intended LAN clients.

For example, to serve from a host at 192.168.1.20, configure a client to use that address. If you administer a Linux client using chrony, add a source to its configuration:

server 192.168.1.20 iburst

Reload or restart the client's time service using its normal administration procedure. On that client, chronyc sources -v and chronyc tracking can show source selection and measured offsets. Compare against another independent trusted reference while evaluating accuracy.

Timing Limits​

Observer currently advertises stratum 1 and reference ID GNSS unconditionally. Those fields do not prove the receiver is currently locked. If GNSS is unavailable and Observer uses NTP fallback, it still advertises the same values. Monitor actual GNSS status instead of inferring it from NTP response labels.

USB and serial buffering can create a systematic offset. Delay Control adds a signed correction in microseconds to the served clock. Derive the sign and magnitude from measurements; there is no universal correction value. Software timestamps, scheduling, and network path asymmetry limit accuracy even with GNSS.

For private remote access, the embedded Tailscale Service can forward 123/udp. Consider VPN latency when evaluating precision. Keep the service limited to intended clients.