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July 28th, 2014: GPS Week Rollover July 2014

Filed under: General

GPS week rollover happened this weekend, Jul 26 – 27 2014. Users with outdated firmware could experience an issue with the reported GPS week showing as year 1980. It is highly recommended that is you experience this issue, you need to check your firmware version and see if an update is available.

Additional Info

GPS Time is reported in weeks since Jan 6, 1980. The GPS ICD defined navigation data format limits the number of weeks before a roll over to 1023. This means that roughly every 19 years the GPS week goes back to zero and starts incrementing again. In order to help the receiver determine the actual calendar date we have historically used a hard coded date as a reference to figure out which GPS “era” we are in (pre 1999 or post 1999). From time to time we would update the baseweek of a new version of firmware and this would provide 10-18 years after that date before the receiver would no longer be able to figure out the correct GPS era. Again, the receiver continues to function but the GPS week is reported as a raw number between 0 and 1023 instead of the number of weeks since January 6, 1980.

Where can I find firmware updates for my GPS receiver?