Logo PTB
View of the Mainflingen long-wave radio station for transmission of the DCF77 signal: transmitter building (in the back), antenna building (yellow bricks) and antenna masts.

International Time Comparisons

On the international level, the time institutes identified in the above figure by acronyms participate in the realization of the international reference time scale TAI und UTC. Each connecting line represents a time comparison evaluated on a regular basis by the Bureau International des Poids et Mesures (BIPM). A simple line stands for a time comparison via GPS, a multiple line refers to a time comparison via a geostationary telecommunication satellite.

In addition, institutes may of course agree upon and perform additional direct time and frequency comparison on a bilateral basis. Moreover, BIPM calculates ”strategically“ important connections to increase reliability with the aid of all available technologies; details can be found on the web-site of BIPM Section Ti