Quantum-based Accelerometers for Satellite Gravimetry Missions

Accelerometers are an essential component of satellite gravimetry missions, as the non-gravitational forces acting on the satellites must be known in order to determine the Earth's gravity field. However, the accelerometers currently in use are one of the limiting factors regarding the accuracy of the determined gravity field, which opens up room for improvement. Among other techniques, quantum-based accelerometers are promising candidates to be applied in the future. In order to achieve the required technology readiness level for operation in space, a pathfinder mission is planned to demonstrate the technology. This mission is being prepared in the framework of the Cold Atom Rubidium Interferometer in Orbit for Quantum Accelerometer - Pathfinder Mission Preparation (CARIOQA-PMP) project funded by the European Union. In addition to designing the pathfinder mission and instrument to achieve a specific performance, simulations are carried out based on the expectable performance not only for the pathfinder mission but also beyond on the utilisation of quantum-based accelerometers in future satellite gravimetry missions. This includes a broad study on different mission types, such as a single satellite with high-low satellite-to-satellite tracking, as foreseen in the pathfinder mission, or a satellite constellation with GRACE-FO-like conditions utilising low-low satellite-to-satellite tracking. Here, closed-loop simulations are used to investigate under which conditions the determined gravity field solution benefits from a quantum-based accelerometer compared to a classical electrostatic one and which challenges still need to be addressed in order to improve resolution and accuracy.