Demonstration of a Robust Hybrid Classical/Quantum Accelerometer

We present a hybrid accelerometer that combines the large bandwidth and dynamic range of a mechanical accelerometer with the extreme stability of a quantum accelerometer based on cold atom interferometry. We describe our experimental setup and hybridization algorithm and, to assess the performances of the apparatus, we simulate a mobile environment in the laboratory by adding simultaneously vibration noise, temperature variations and laser intensity fluctuations. Even under these conditions, we are able to track the accelerometer bias to less than $1 \mu \mathrm{g}$. In a normal laboratory environment, our hybrid accelerometer then reaches a precision of 10 ng after 11 hours of integration. Finally, we present a novel system that compensates in real-time phase shifts due to vibrations and Doppler shifts that occur when changing the AI orientation. This allows us to operate optimally the atom interferometer in an arbitrary direction, opening the way toward truly mobile operation.