Absolute frequency measurement with uncertainty below $1\times 10^{-15}$ using International Atomic Time

Hidekazu Hachisu, Gérard Petit, Tetsuya Ido

The absolute frequency of the ${}^{87}\mathrm{Sr}$ clock transition measured in 2015 was reevaluated using an improved frequency link to the SI second. The scale interval of Internation…