Home» About NSC "Institute of Metrol...» News» About possible problems with the performance of terrestrial receivers of the Global Positioning System (GPS) April 6, 2019 (UTC)

Owners, operators and other users who receive World Coordinated Time (UTC) from the Global Positioning System (GPS) must be aware that on April 6, 2019, the GPS will reset the weekend.

The GPS navigation message has a decimal point that represents the number of the week. The valid range of values ​​for the week parameter is from 0 to 1023 (or 1024 total values). The week parameter is incremented by one unit each week. At the end of the 1024th week, the parameter returns to its original state to 0. Thus, the weekly parameter in the GPS system returns to zero every 1024 weeks starting on January 6, 1980.

Possible effect of reset GPS GPS parameter

Depending on the specification on the ISGPS-200H, the ISGPS-200 Navstar GPS space segment can either be reset or damaged. However, the test of some GPS devices has shown that not all device manufacturers will be able to adapt to the reset of the weekend of April 6, 2019. In addition, some device manufacturers interpret the week's parameter for a date different from January 5, 1980. These devices should not be affected by resetting the room on April 6, 2019, but may experience a similar reset in the future. For example, a certain GPS device may interpret the week's parameter as to the date of the firmware creation, and will have such a reset problem 1024 weeks after the date of creation of this firmware.


Owners, operators and users are strongly encouraged to:

1. Explore and understand their possible GPS dependencies to get UTC and the performance of their systems.

2. Contact manufacturers of GPS devices that they use to get UTC:

a) understand the readiness of the manufacturer to the fact that on April 6, 2019 in the GPS system will reset the number of the week,

b) understand the actions necessary to ensure the proper operation of equipment associated with obtaining information from GPS after April 6, 2019

3. Make sure that the GPS firmware has been updated to the latest releases.


A memorandum for US owners and operators using GPS to receive UTC time