Recommendation 2 of the 20th CCTF (2015)

Predictions of UTC disseminated by Global Navigation Satellite Systems (GNSS)

The Consultative Committee for Time and Frequency (CCTF),

considering that

• the task of the BIPM is to ensure world-wide uniformity of measurements and their traceability to the International System of Units (SI),
• two GNSS already exist and others are under development,
• at least two additional GNSS – BeiDou and Galileo – currently offer or are close to offering services,
• Section 5 of BIPM Circular T publishes the relationship between UTC/TAI and the predictions of UTC(k) disseminated by GPS and GLONASS;

aims to

• facilitate access for any user to real-time predictions of UTC disseminated by existing and future GNSS;

recommends that

• Section 5 of BIPM Circular T be retitled “Relations of UTC and TAI with predictions of UTC disseminated by GNSS”, and adds similar information on new GNSS as they become operational.