GPS Rollover Problem

The Week Rollover Problem is a known issue caused by the way that GPS used to handle the week element of the data that forms an essential part of the navigation signal. GPS used a 10-bit field to encode the week number in each GPS time message, which means that a maximum of 1,024 weeks (19.7 years), could be handled. Each of these periods is known in GPS terms as an “epoch”. At the end of each epoch of 1,024 weeks, the receiver resets the week number to zero and starts counting again.The first GPS satellites went live on 6th January 1980, meaning that the first epoch of GPS time lasted until 21st August 1999. We are now nearing the end of the second epoch, which will fall on the 6th April 2019.

Analysis for NetModule Routers showed, that time and location information provided by our GNSS enabled Routers are not affected by the Rollover effect 6th April 2019.

However, some GNSS chipsets show an invalid time from November 2019. NetModule has implemented a bug fix and corrected the time information in the NMEA data. Release History: http://wiki.netmodule.com/documentation/releases

(Updated 04.11.19)