A subsequent communication posted on the European GNSS Service Centre said Galileo service had been affected, “by an anomaly in the time determination function of the ground segment of the system.”
The communication went on: “This resulted in signals flagged as MARGINAL (SISA=NAPA) for all satellites. During this period, pseudorange errors in excess of nominal performance were experienced by user receivers.
“The system was reconfigured and restored to a nominal situation as of Dec 14, 06:00 UTC. A NAGU [NOTICE ADVISORY TO GALILEO USERS] will be published shortly with the exact chronology of the event. Further communication will be published as the investigation on the root cause for the event and its effect on the service progresses.”