Meinberg receivers ready for GPS Week Number Rollover

Photo: Meinberg

On April 6, the GPS system used by many organizations for critical infrastructure will perform a rollover. The rollover is the result of a legacy GPS navigation message which gives a week number as a 10-bit parameter.

As a result, the week number parameter in the GPS navigation message needs to reset to zero every 1024 weeks. That means from that date onwards, users are likely to start seeing rollover problems in GPS receivers that aren’t programmed to cope with the week number reset.

Meinberg, a GNSS receiver maker based in Germany, has a different approach with its GPS receivers. Instead of a 10-bit parameter, Meinberg’s firmware uses a 16-bit week number, and it is incremented at the end of each week.

This means that by the first rollover on Aug. 21, 1999, the week number sent by the satellites rolled from 1023 back to 0, while the internal (Meinberg) week number simply counted to 1024, then to 1025 and so forth. So, on April 6, the GPS week counter will reset to 0, but Meinberg’s internal one, which will have been reached the value of 2047 by that time, will continue to count in a consecutive order.

More information about the GPS Week Number Rollover can be found on our Meinberg’s Knowledge Base.