Recommendation 6 of the 18th CCTF (2009)

Relationship of predictions of local timescales UTC(<i>k</i>) as disseminated by Global Navigation Satellite Systems, to the international reference time scales Universal Coordinated Time (UTC) and International Atomic Time (TAI)

The Consultative Committee for Time and Frequency,

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 Global Navigation Satellite Systems (GNSS) already exist and others are under development;
• existing operational GNSS disseminate predictions of local timescales UTC(k), e.g. GPS disseminates predictions of UTC(USNO) and GLONASS disseminates predictions of UTC(SU);
• Section 5 of BIPM Circular T publishes the relationship between UTC, TAI and the GNSS System Times (ST);

aiming to

• facilitate access for all users to predictions of UTC(k) as disseminated by existing and future GNSS;

recommends that

• Section 5 of Circular T include information on the relationship of UTC and TAI with the predicted UTC(k) disseminated by the GNSS;
• Section 5 of Circular T be renamed “Relations of UTC and TAI with predictions of UTC(k) disseminated by the GNSS and their System Times”.

DOI : 10.59161/CCTF2009REC6E