NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: GPS shortcomings.
From: Lu Abel
Date: 2005 Jun 8, 12:35 -0700
From: Lu Abel
Date: 2005 Jun 8, 12:35 -0700
George and list: There's mention of this failure (due to the failure of the atomic clock on one of the satellites) in www.ion.org/sections/southcalifornia/ lavrakas_civil_gps_monitoring.ppt I was rather surprised to learn that there is NOT continuous monitoring of the GPS system for integrity of its positioning information, given that there's a whole new generation of air traffic control that's going to be based on GPS... Lu Abel George Huxtable wrote: > I know that references to GPS are discouraged, if not forbidden, on this > list. But I wonder if a note about GPS shortcomings would be more > acceptable? > > I've just received a leaflet from the British Lighthouse authorities, > pushing for use of the new Loran-C transmitter at Rugby, England. > > In which is the statement- > > "GNSS systems themselves also suffer occasionally from undetected failures; > for example, a satellite clock error on 1 January 2004 gave rise to errors > in measured positions of up to 45 kilometres in Western Europe for a period > of some 3 hours, resulting in onboard navigational failures." > > I hadn't heard about that event, which sounds rather serious. Is it common > knowledge? Can anyone offer further details? > > It wouldn't have affected me. I would have been by the fireside on that day. > > George. > > ================================================================ > contact George Huxtable by email at george@huxtable.u-net.com, by phone at > 01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy > Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. > ================================================================ > >