NovAtel Service Bulletin – GPS Era Week Rollover, 2019

On April 6, 2019, the transmitted GPS week number in the navigation message will rollover from 1023 to 0. NovAtel commercial receivers will continue to increment the week number from 2047 to 2048 and will not roll back to 0 or 1024. This will be the second era rollover since GPS time was established. In preparation for this event, NovAtel has tested our receivers using a simulator and have determined the following.

NovAtel OEM6 receivers with firmware >= 6.510 and OEM7 receivers will continue to operate as expected during and after the rollover. The week number will continue to increment.

OEM6 receivers with firmware < 6.510, OEMStar, OEMV and OEM4 receivers will continue to increment the week reported and operate normally during and after the rollover. However, one issue was identified where the receivers will report an incorrect week number in the “ref week” field of the RAWALM log if the current week number and the almanac week number are in different eras. The reference week value will be correct once both the current week number and the almanac week number are in the new era. It is recommended that users do not use the reference week value in the RAWALM log, or if it is required, to decode the WNa directly from the SV ID 51 subframe page data. Note: The header of the RAWALM message will be correct and the ALMANAC log is not affected.

Please note that firmware prior to OEM4 2.322 was not tested.

For NovAtel ground reference station receivers, please contact support.

Receiver firmware can be downloaded at the link below
Download link: http://www.novatel.com/support/info/view/gnss-receivers

adminsupport

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