Satellite Failure Behind GPS Timing Anomaly (itnews.com.au)

Bismillah writes: The recent 13-microsecond timing anomaly was caused by a satellite failure triggering a "software issue", the USAF 50th Space Wing has confirmed. Such an error is large enough to cause navigation errors of up to 4 km. Luckily, no issues with GPS guided munition were reported. Reader donaggie03 adds a link to the official explanation from Rick Hamilton, Executive Secretariat of the Civil Global Positioning System Service Interface Committee. From Hamilton's email: Further investigation revealed an issue in the Global Positioning System ground software which only affected the time on legacy L-band signals. This change occurred when the oldest vehicle, SVN 23, was removed from the constellation. While the core navigation systems were working normally, the coordinated universal time timing signal was off by 13 microseconds which exceeded the design specifications. The issue was resolved at 6:10 a.m. MST, however global users may have experienced GPS timing issues for several hours.

Comments

Use for surface navigation

[techno-vampire]

Back in '72, when I was in the Navy, one of my friends was a Quartermaster's Mate, involved in (among other things) navigation. He told me that when we went from Pearl Harbor to Subic Bay, in the Phillipenes, that they used 2000 yards for a Nautical Mile, rather than the more accurate 2025, and treated all turns as "point turns" instead of working out the distance needed to make the turn. When we made our landfall and were able to pinpoint our location, we were within two nautical miles of our location by dead reckoning. This will give you an idea of how little an issue this probably was for ships or aircraft, although it might have been a problem for guided munitions with no human oversight.