2019 GPS Week Rollover

[Chuck - Raymarine - Moderator]

2019 GPS Week Rollover

The GPS Satellite system week counter reaches its count limit of 1023 and will be set to zero on 6th April 2019. The GPS Satellites transmit a week count number from 0 to 1023 which relates to the last Rollover date of 1999 to the next Rollover date of 6th April 2019, (19.7yrs), in which it will once again return to zero and start the count again.
All GPS Receivers use this week count number to calculate the current UTC date. Therefore, the date of launch / manufacture of the GPS chip set built into the GPS Receiver will dictate the date the GPS will roll over. (Date of Launch + 19.7yrs = Rollover date). This in turn will dictate the date error displayed. The 2019 GPS Week Rollover would have a potential effect upon GPS receivers (including GPS sensors and GPS receivers embedded within MFDs, chartplotting products, AIS receivers, and VHF radios).

You should note that any features which are dependent upon date/time information could be potentially affected by the incorrect date caused by this rollover.

local variation
tide / current data
waypoint/route creation date
Date data item

If you note a slow acquisition of GPS FIX or inaccurate GPS FIX - reflected in a high HDOP value (which is typically 1.0 or less for an accurate fix), this may be corrected by commanding the GPS to restart.

Whether a GPS receiver will be subject to 'rollover' is based on the make/model of GPS receiver which has either been constructed into the product or the product has been connected to and the GPS chipset used in it's manufacture. Accordingly, should one determine that the date/time information reported by the system is incorrect following the 2019 GPS Week Rollover event (April 6, 2019), then it may be necessary to either replace the system's GPS sensor, add an external GPS sensor to the system, or replace the GPS sensing device (should no software/firmware update be available to address the 2019 GPS Week Rollover event).

Raymarine is pleased to advise that none of the current products that include a GPS Receiver are impacted by the impending GPS week count rollover in April 2019. That includes the Axiom & Element MFDs, Dragonfly, RS150, AR200 & AIS700. Recent products such as the a/c/e/eS/gS MFDs, RS130, AIS650 are also not affected.

Should a system's GPS receiver be affected, then most affected systems may be addressed by adding a Raystar 150 GPS Sensor to the system or replacing the currently installed GPS sensor with a Raystar 150 GPS Sensor.

Please refer to the attached table to identify if your product is affected and the actions required


RAYFAQ#