<Mir16609@aol.com> wrote: > In a message dated Wed, 14 Feb 2001 10:53:41 AM Eastern Standard Time, "Jim King" <jim@jimking.net> writes: > > //////////////////////////////////// > Most consumer handheld GPS receivers update their displays at a relatively > low priority. The displayed time is often off by several hundred > milliseconds, and (in rare cases) off by several seconds. > ////////////////////////////////// > > Actually not so rare. > > GPS units are set to the proper time at manufacture but do not adjust for the leap seconds that are added every 2-3 years. The last leap second was added on January 1st, 1999. > > See: > http://tycho.usno.navy.mil/leapsec.html In recent times leap seconds have been inserted every 18 months. The number of seconds offset between UTC and GPS time is part of the GPS data stream. A properly designed receiver will use the offset from the data message and not a hard-coded offset from the factory. I haven't seen a recent GPS receiver that uses a hard-coded offset, although I'm sure there are a few out there. Jim ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
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