Title: Calibration of atomic trajectories in a large-area dual-atom-interferometer gyroscope,
Abstract: We propose and demonstrate a method for calibrating atomic trajectories in a
large-area dual-atom-interferometer gyroscope. The atom trajectories are
monitored by modulating and delaying the Raman transition, and they are
precisely calibrated by controlling the laser orientation and the bias magnetic
field. To improve the immunity to the gravity effect and the common phase
noise, the symmetry and the overlapping of two large-area atomic interference
loops are optimized by calibrating the atomic trajectories and by aligning the
Raman-laser orientations. The dual-atom-interferometer gyroscope is applied in
the measurement of the Earth rotation. The sensitivity is $1.2\times10^{-6}$
rad/s/$\sqrt{Hz}$, and the long-term stability is $6.2\times10^{-8}$ rad/s $@$
$2000$ s.