The Global Positioning System time epoch is ending and another one is beginning, an event that could affect your devices or any equipment or legacy system that relies on GPS for time and location.
Most clocks obtain their time from Coordinated Universal Time (UTC). But the atomic clocks on satellites are set to GPS time. The timing signals you can get from GPS satellites are very accurate and globally available. And so they’re often used by systems as the primary source of time and frequency accuracy.
When Global Positioning System was first implemented, time and date function was defined by a 10-bit number. So unlike the Gregorian calendar, which uses year, month and date format, the GPS date is a “week number,” or WN. The WN is transmitted as a 10-bit field in navigation messages and rolls over or resets to zero every 1,204 weeks.
Since that time, the count has been incremented by one each week, and broadcast as part of the GPS message.
The GPS week started January 6, 1980 and it became zero for the first time midnight August 21, 1999. At midnight April 6, the GPS WN is scheduled to reset, which could be problematic for legacy systems and …read more
Source:: TechCrunch Gadgets
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