Towards a realistic noise modelling of quantum sensors for future satellite gravity missions

Cold Atom Interferometry accelerometers and gradiometers have emerged as promising candidates for future gravimetric satellite missions due to their potential for detecting gravitational forces and gradients with high precision and accuracy. Mapping the Earth's gravity field from space offers valuable insights into climate change, hydro- and biosphere evolution, and seismic activity prediction. Current satellite gravimetry missions have demonstrated the utility of gravity data in understanding global mass transport phenomena, climate dynamics, and geological processes. However, state-of-the-art measurement techniques face noise and long-term drift limitations, which might propagate on the recovery of Earth's time-varying gravity field. Quantum sensors, particularly atom interferometry-based devices, offer promise for improving the accuracy and stability of space-based gravity measurements. This study explores the sensitivity of CAI accelerometers and gradiometers. We explore the low-low satellite-to-satellite and gravity gradiometry measurements to build analytical models of measurements and associated errors. We selected an ambitious scenario for CAI parameters that illustrates a potential path for increasing instrument accuracies and capabilities for space gravimetry. Two operational modes, concurrent and sequential, are compared to mitigate the effects of inaccurately known attitude rates on Coriolis accelerations. The sequential mode shows the potential to reduce these effects, enabling accurate measurements for low-low Satellite-to-Satellite Tracking missions in the near future. Attitude determination is discussed, highlighting the importance of accurate measurements to reconstruct Coriolis accelerations and related to errors in the reference frame rotation from body or local frames to the Earth co-rotating frame.