Continuous gravity measurement with a portable atom gravimeter

We report here a portable and robust home-built atom gravimeter (USTC-AG11) continuously working in a seismic station in Zhaotong, Yunnan, for over five months. Based on the principle of matter-wave interference, the atom gravimeter is very sensitive to the local gravity and reaches the precision of micro-Gal (1 x 10-8m/s2) level. With the technique of vibrational compensation, the sensitivity of the atom gravimeter root reaches 38 mu Gal/ Hz, the overall noise level is suppressed by 80% compared to the no-vibration-compensation method, and 95% of the vibration noise is effectively suppressed. The design of the atom gravimeter in the electronics and laser optics, especially the laser frequency and phase auto-relock technology, guarantees long-term continuous running. The long-term precision of the atom gravimeters is better than 2 mu Gal, which is comparable to the best classical gravimeter FG-5(X). Our work provides an application for the high-precision atomic gravimeter based on modern quantum sensing technology in the field of geophysics and geodesy survey.