New CCL-CCTF Application Programming Interface prototype web service is now available

The mises en pratique for the metre and the second are now machine-readable.

First official use of Galileo measurements in the computation of Coordinated Universal Time

Progress towards a continuous coordinated universal time

Two new publications deal with the needs and roadmap towards a continuous UTC.

New plot from the BIPM Time Department illustrates the accuracy of TAI and UTC

The plot allows the monitoring of the accuracy of the TAI scale interval with respect to realizations of the SI second by PSFS.

Human- and machine-readable key comparison reports using the PDF/A-3 format

The BIPM is pleased to announce the publication of the first key comparison report embedding machine-readable versions of the document.

Record number of frequency standards contribute to International Atomic Time

In November 2021 a new record of sixteen different frequency standards operated by eleven laboratories contributed to the accuracy of International Atomic Time TAI. They include three recently developed optical lattice clocks. This achievement is another step towards a future redefinition of the second.

New radio techniques allow frequency comparison of distant optical clocks

An international collaboration between the NICT, INRIM, INAF and BIPM has successfully achieved the frequency comparison of distant optical clocks using two independent radio techniques, VLBI and IPPP.

Two-Way Satellite Time and Frequency Transfer: first use of a Software Defined Radio receiver in UTC calculation

Two-Way Satellite Time and Frequency Transfer, improved by the Software-Defined Radio (SDR) receiver, has been used for Circular T calculation for the first time in March 2020.

BIPM Time Department provides additional information on the use of PSFS in UTC

Starting from March 2020, the BIPM Time Department is providing additional graphical information concerning the use of Primary and Secondary Frequency Standards (PSFS) in UTC.