Extended Data Fig. 3: Extrapolations over dead times using the masers as a flywheel.
From: Intercontinental comparison of optical atomic clocks through very long baseline interferometry
a, Uptimes of IT-Yb1 (yellow), optical link (green), VLBI link (blue) and NICT-Sr1 (red) marked as colored regions as a function of MJD. Gray horizontal bars represent evaluation intervals corresponding to each VLBI session, as marked by a vertical notch. For each evaluation interval the extrapolation was calculated for the masers at INRIM (between IT-Yb1 and the optical link), INAF (between the optical link and VLBI), and NICT (between VLBI and NICT-Sr1). b, Noise models used for extrapolations for the masers at INRIM, INAF, and NICT, describing the Hadamard variance σH2 = h −2(τ/s)−2 + h−1(τ/s)−1 + h0 + h2(τ/s)2.
