Recommendation 6 of the 18th CCTF (2009)

Relationship of predictions of local timescales UTC(k) 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