Hybrid Electrostatic–Atomic Accelerometer for Future Space Gravity Missions

Abstract

Long-term observation of Earth’s temporal gravity field with enhanced temporal and spatial resolution is a major objective for future satellite gravity missions. Improving the performance of the accelerometers present in such missions is one of the main paths to explore. In this context, we propose to study an original concept of a hybrid accelerometer associating a state-of-the-art electrostatic accelerometer (EA) and a promising quantum sensor based on cold atom interferometry. To assess the performance potential of such an instrument, numerical simulations were performed to determine its impact in terms of gravity field retrieval. Taking advantage of the long-term stability of the cold atom interferometer (CAI), it is shown that the reduced drift of the hybrid sensor could lead to improved gravity field retrieval. Nevertheless, this gain vanishes once temporal variations of the gravity field and related aliasing effects are taken into account. Improved de-aliasing models or some specific satellite constellations are then required to maximize the impact of the accelerometer performance gain. To evaluate the achievable acceleration performance in-orbit, a numerical simulator of the hybrid accelerometer was developed and preliminary results are given. The instrument simulator was in part validated by reproducing the performance achieved with a hybrid lab prototype operating on the ground. The problem of satellite rotation impact on the CAI was also investigated both with instrument performance simulations and experimental demonstrations. It is shown that the proposed configuration, where the EA’s proof-mass acts as the reference mirror for the CAI, seems a promising approach to allow the mitigation of satellite rotation. To evaluate the feasibility of such an instrument for space applications, a preliminary design is elaborated along with a preliminary error, mass, volume, and electrical power consumption budget.

Microgravity facilities for cold atom experiments

“…Such systems enable the study of weak trapping potentials and observing atomic ensembles after long evolution times. This, in turn, may allow for very low temperatures [25] and large scale factors in atom interferometry [26][27][28][29]. Space-borne atom interferometers were proposed for testing the UFF [30,31], Earth observation [32][33][34], dark matter and dark energy search, and cosmology [35] has been proposed.…”

Rotation related systematic effects in a cold atom interferometer onboard a Nadir pointing satellite

“…As expected, the Coriolis acceleration due to Ω y vanishes for Ω M = −Ω y . Besides, a term (11) corresponding to the motion of the mirror in the satellite appears in the phase expression. The centrifugal acceleration due to Nadir rotation around y axis is compensated only when this term is equal to x 0 Ω 2 y , which requires Ω M = Ω I = −Ω y , but also x M = 0.…”

“…Their sensitivity and accuracy are expected to increase dramatically in microgravity, where the interrogation time is no longer limited by the size of the instrument 2,3 . This triggered a recent interest in developing this technology for space [4][5][6] with potential applications in geodesy [7][8][9][10][11] , fundamental physics 12,13 , navigation and gravitational wave observation 14,15 . Opening the way to those developments, the CARIOQA Pathfinder Mission 16 aims at realizing the first quantum accelerometer on a satellite.…”

Airborne Absolute Gravimetry With a Quantum Sensor, Comparison With Classical Technologies

“…It has also been demonstrated that such technology could be implemented on moving vehicles like spring gravimeters or forced balanced accelerometers (Bidel et al., 2018, 2020; Huang et al., 2022). Atom interferometry technology is finally also studied for the next generation of sensor for space gravimetry (Lévèque et al., 2021; Reguzzoni et al., 2021; Trimeche et al., 2019; Zahzam et al., 2022).…”