UK: The General Lighthouse Authorities (GLA) of the UK and Ireland have issued a map illustrating the effects of last week's failure in GLONASS system. Satellites of the GLONASS network experienced a half-day outage when bad data was uploaded to spacecraft.
Above: A GLONASS receiver (red dot) on England's east coast gave position fixes in the North Sea (blue triangles)
The GLA map shows a GLONASS receiver at Harwich giving corrupted position fixes that were off by more than 50km. The Authorities say the event of April 2 is a timely reminder that alternatives to satellite navigation are essential. The GLA themselves are supporting a system in the UK and Ireland called eLoran, which transmits long-range position, navigation and timing signals from a ground-based radio network. Its primary use is for ships and others in the maritime sector, but there is a feeling also that eLoran could provide a robust back-up for GPS, GLONASS, and Galileo when it arrives.