Combined Classical and Quantum Accelerometers For the Next Generation of Satellite Gravity Missions

TL;DR

This paper proposes a hybrid classical-quantum accelerometer system for satellite gravity missions, demonstrating significant improvements in gravity field mapping by combining long-term stability of quantum sensors with the high bandwidth of classical sensors.

Contribution

It introduces a comprehensive simulation of hybrid accelerometers considering satellite rotation, gravity gradient, and self-gravity, advancing beyond previous simplified models.

Findings

Hybrid accelerometers improve gravity solutions by 10-100 times.

Significant reduction in striping artifacts in gravity maps.

Enhanced long-term stability and measurement accuracy.

Abstract

Cold atom interferometry (CAI)-based quantum accelerometers are very promising for future satellite gravity missions thanks to their strength in providing long-term stable and precise measurements of non-gravitational accelerations. However, their limitations due to the low measurement rate and the existence of ambiguities in the raw sensor measurements call for hybridization of the quantum accelerometer (Q-ACC) with a classical one (e.g., electrostatic) with higher bandwidth. While previous hybridization studies have so far considered simple noise models for the Q-ACC and neglected the impact of satellite rotation on the phase shift of the accelerometer, we perform here a more advanced hybridization simulation by implementing a comprehensive noise model for the satellite-based quantum accelerometers and considering the full impact of rotation, gravity gradient, and self-gravity on the instrument. We perform simulation studies for scenarios with different assumptions about quantum and classical sensors and satellite missions. The performance benefits of the hybrid solutions, taking the synergy of both classical and quantum accelerometers into account, will be quantified. We found that implementing a hybrid accelerometer onboard a future gravity mission improves the gravity solution by one to two orders in lower and higher degrees. In particular, the produced global gravity field maps show a drastic reduction in the instrumental contribution to the striping effect after introducing measurements from the hybrid accelerometers.