BIPM - Time Department FTP server

– the intergovernmental organization through which Member States act together
on matters related to measurement science and measurement standards.

FTP server of the BIPM Time Department

TT(BIPM) is a realization of Terrestrial Time as defined by the International Astronomical Union (IAU). It is computed annually by the BIPM, based on a weighted average of the evaluations of the frequency of TAI by the primary and secondary frequency standards. It is mostly used in scientific applications requiring long-term frequency stability and high frequency accuracy.

Last computed TT(BIPMXY) and older computations can be accessed below :
(Each computation is identified by the string XY where 19XY or 20XY is the last year of data included)

For more information please see the Readme file .
Older files can be accessed directly from the ftp site: ftp2.bipm.org/pub/tai/ttbipm/.

Other international metrology data centres:

International metrology publications

Guides in metrology

IERS Conventions Center

Recommended values of standard frequencies

Related articles

International reference timescales

Recent publications of the BIPM Time Department

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