Impact of atomic clock and time-transfer noises in the formation of the international atomic time

Abstract

The Bureau International des Poids et Mesures (BIPM), is on charge of computing and publishing international reference time scale. A practical scale of time for world-wide use has two essential elements: a realization of the unit of time and a continuous temporal reference. The reference used is International Atomic Time (TAI), a time scale calculated at the BIPM using data from some three hundred atomic clocks in over fifty national laboratories. TAI is a uniform scale. The Coordinated Universal Time (UTC) is obtained by adding to TAI leap seconds due to slightly irregular rotation of the Earth. The contributing clocks located around the world, mostly in hemisphere north, are compared by different satellite time transfer techniques. Clocks and transfer techniques are affected by various types of noise. This paper briefly reports the impact of these noises on the computation of TAI.