GPS World
–
One new potential wrinkle for Galileo was hinted at during the Munich Satellive Navigation Summit session in March on legal issues around GNSS timing. A recent GPS timing issue caused numerous problems for digital broadcasters and financial networks around the world on Jan. 26, when a data upload went slightly awry. This introduced a 13.7 millisecond error in one of the timing signals: the static offset for GPS time compared to Coordinated Universal Time (UTC). It led to some receivers exhibiting “different and unwanted behaviour” — a very polite description!
Fortunately the issue was resolved swiftly, and correct data uploaded. The extent of any financial losses and how any legal proceedings (if any) to recover damages might pan out are still unclear. However ,what is clear is that while GPS time has a clear link to legal time, Galileo does not. Dr. Andreas Bauch from the German Physikalisch-Technische Bundesanstalt (PTB) — one of Germany’s “Time Lords” — described the underlying legal basis of GNSS time.
U.S. GPS time is traceable and legally defined to national time and UTC through the National Institute of Standards and Technology (NIST). In Europe most Member States, but not all, have legal time defined in legislation. Galileo System Time (GST) is not linked to a single institution but to an average derived from a network of European standards institutions including PTB. From the presentations it was not clear to me if GST currently has a water-tight legal definition.
Talking to legal and technical experts after this session, it became clear that the legal basis for GST does need to be clearly defined in European legislation — and soon — if Galileo PNT services are to be a commercial reality in the near future. The commission needs to get on the case for this one pronto.
