GPS Week Rollover 2019

All Aplicom A-series products (A1, A9, A11) will operate normally during and after the GPS week rollover.

The Global Positioning System (GPS) includes the ability to transmit the proper date and time to a receiver by supplying the receiver with the current week and the current number of seconds into the week. This allows the receiver to translate the date and time into a more typical format – day, month, year, and time of day.

However, the week number is encoded into the data stream by a 10-bit field.  A binary 10-bit word can represent a maximum of 1,024 weeks, which is approximately 19.7 years.

GPS week zero started in January 1980 and the 1024 weeks counter ran out and rolled over on August 21, 1999. The week counter then reset to zero, and it has been recounting ever since. The next time the counter will reach week 1023 and rollover to zero is on April 6, 2019.

It is important that GPS receivers operate without any disruptions during this transition and also come up and navigate correctly if powered off during the transition and then powered on after the roll over occurred.