Satellite gravimetry missions have significantly enhanced our understanding of the Earth’s gravity field and its dynamics. It became crucial for geosciences to extend the time series with successor missions, accompanied by reviewing the factors for improvement of the temporal and spatial resolution of the data. The accelerometers on board, measuring the non-gravitational forces, have become a limiting factor on the instrumental side. Here, quantum-based sensors provide a promising technique that could replace or be combined with the commonly used electrostatic accelerometers to advance the measurements. The Cold Atom Rubidium Interferometer in Orbit for Quantum Accelerometry (CARIOQA) initiative in the Horizon Europe funding programme aims to launch a quantum pathfinder mission in order to raise the technology readiness level of a quantum accelerometer and to further pave the way of a future quantum space gravimetry mission. As part of the ongoing Pathfinder Mission Preparation (CARIOQA-PMP) project, among investigations on the instrument and satellite side, the scientific advantages of a quantum accelerometer for geodetic purposes are studied comprehensively. Both the pathfinder mission, a single satellite utilising high-low satellite-to-satellite tracking, and a future quantum space gravimetry mission, a constellation of satellites operating in low-low satellite-to-satellite tracking mode, are analysed. For this purpose, closed-loop simulations combining orbit integration and gravity field recovery are carried out. Based on the results, the performance of the cold atom interferometer can be evaluated and compared with other types of accelerometers, thus identifying its benefits and remaining challenges. We acknowledge the funding by the European Union for the project CARIOQA-PMP (Project-ID 101081775).

Authors: Nina Fletling¹, Annike Knabe¹, Jürgen Müller¹, Matthias Weigelt², Manuel Schilling² (¹Leibniz University Hannover, Institute of Geodesy, Hannover, Germany; ²German Aerospace Center (DLR), Institute for Satellite Geodesy and Inertial Sensing, Hannover, Germany)