Comparison with TAI of NTSC-F1

Abstract

Frequency measurement and comparison with TAI of NTSC-F1 is presented in the paper. Automatical evaluation system of cesium fountain clock is designed to correct the systematic frequency biases in real time. The estimation of the average frequency between H-maser donated as 296 in Circular T report and NTSC-F1 is obtained over the frequency data after correcting all the shifts. Then the frequency offset between NTSC-F1 and TAI is given with the uncertainty of $2.9\times 10^{-15}$ including the uncertainty between UTC and UTC(NTSC).