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2019 GPS week number rollover

How our video overlay units were affected

In 2019 all of our GPS video overlay units which had integral GPS receivers, shown below, were affected by the GPS week number rollover. The GPSBOXSPRITE3-U precision timing unit was not affected.
GPS Rollover explained




As all these units used the same GPS receiver we regret that they will all now show dates starting from 22/08/99 from 07/04/19 onwards. The time of day will be correct. This error is caused by the way GPS time represents the current week number using only 10 bits. As a result only 1024 weeks of elapsed time since the last rollover on August 22nd 1999 can be represented before it rolls over again. The GPS receiver is internally using the same GPS time message as the rest of the GPS system for its calculations. As a result the navigation computations which produce position, speed, altitude and heading data remain correct. The error is in how the GPS time data is translated into UTC time by the GPS receiver in our units.

Example of the the error. Actual date was 08/04/19, other data correct.

There is nothing users can do to correct this error. As many DVR systems can generate a time and date stamp on their recordings, we recommend turning off the time and date line of the GPS overlay display and using the DVR time stamp. There is no other immediate user solution.
We regret that we were unable to predict that this error would occur. We have amended our units firmware to account for the error and a replacement microcontroller can be purchased to provide a solution immediately to users whose units are no longer under warranty.



© The BlackBoxCameraTM Company Limited 2020