Quantum Gravimetry

Quantum gravimetry ©Tim Jensen
Quantum Gravimetry Field Trip ©Tim Jensen

Contact

Tim Enzlberger Jensen

Tim Enzlberger Jensen Senior Researcher

René Forsberg

René Forsberg Professor

The gravity group is actively involved in activities related to quantum technology and has a close collaboration with the French Aerospace Lab, ONERA, who developed a moving-base gravimeter based on cold-atom interferometry for marine and airborne surveys. The first successful airborne survey using quantum gravimetry was demonstrated in Iceland in 2017 and several successful campaigns have followed. Currently, we are involved in several research projects concerning both new developments and demonstrations of current technologies.

Adequade

The Advanced, Disruptive and Emerging QUAntum technologies for Defense (ADEQUADE) project focuses on Quantum Sensing for defense applications and spans three domains: (1) Positioning, Navigation, and Timing quantum sensors, (2) Quantum Radio Frequency sensing, and (3) Quantum optronics sensing. DTU is involved in a work package dedicated to the development of a second-generation quantum gravimeter, with tasks related to processing, development, and simulations.
The project is funded by the European Defense Fund (EU-EDF). More information can be found on the project website: https://adequade.eu/

EQUIP-G

The European QUantum Infrastructure Project for Gravimetry (EQUIP-G) project represents the first step towards the establishment of European network of gravimeters based on quantum technology. The consortium will acquire several new terrestrial quantum gravimeters and gradiometers along with a moving-base gravimeter for marine and airborne measurements. These gravimeters will be acquiredcommercially. During the project, nine use cases are conducted to demonstrateboth the usefulness of networking gravimeters and the advantages of quantum technology with respect to classical gravimeters. These use cases span a wide range of applications within hydrology, volcanology, geodesy, geothermal energy, climate and airborne surveys.
The main tasks of DTU are related to demonstrating climate monitoring, consisting of repeated measurements in Greenland, and two airborne campaigns using both a fixed-wing aircraft and an airship carrier.
An important aspect of the project is the inclusion of the entire European community through dissemination, communication and workshops, including two training workshops with hands-on exercises. The project is funded by the Horizon Europe programme.

CARIOQA-PMP

The Cold Atom Rubidium Interferometer in Orbit for Quantum Accelerometry – Pathfinder Mission Preparation (CARIOQA-PMP) aims to pave the way for Cold Atom Rubidium Interferometry (CAI) in space. During the preparation of the CARIOQA-PM, the CAI technology is developed further and a roadmap for quantum space gravimetry missions is established. DTU Space is involved in the analysis and simulation of potential mission scenarios for the Quantum Pathfinder Mission and future Post-Pathfinder scientific missions.

CARIOQA-Quantum pathfinder

Green Quantum

The Green Quantum project was funded by the Danish Ministry of Defence Acquisition and Logistics Organization (DALO) with the aim of demonstrating quantum gravimetry for defense applications. The main component of the project consisted of an airborne survey covering the fjord system around the capital of Greenland. This was done in collaboration with ONERA. The collected gravity data were used for several purposes: (1) to support the creation of a new vertical reference system around the Nuuk area; (2) to investigate the impact of gravity information when navigating in GNSS-denied areas; and (3) to support the development of a new quantum gravimeter within the ADEQUADE project by exposing the sensor to new environments.

AirQuantumGrav

The aim of AirQuantumGrav project was to validate the benefits of quantum technology for airborne gravimetry. The project consisted of an airborne survey in Iceland carried out in combination with the Green Quantum survey. The survey lines mainly targeted areas of known mass variations: (1) Repetition of the 2017 survey over the Vatnajökull ice cap; (2) overflying the Askja volcano which is associated with rapid uplift rates; (3) overflying the Fagradalsfjäll volcano which had several recent eruptions; and (4) repeating a survey line between Snæfjellsjökull and Akureyri, which was also surveyed in 2017. The project was funded by the European Space Agency (ESA).

Link to project page: https://doi.org/10.57780/esa-58c58c5

Airborne Survey of French Biscay and Pyrenees

Following the 2017 survey in Iceland, several updates and modifications was performed to improve the performance of the GIRAFE sensor in an airborne environment. In 2019 another airborne survey was carried out in France, with support from Centre Nationale D’étudesSpatialies (CNES) and the European Space Agency (ESA).

Airborne Survey in Iceland

The 2017 airborne survey in Iceland was the first demonstration of airborne gravimetry and was funded by the European Space Agency (ESA). The aim of the project was to test the GIRAFE quantum gravimeter developed by ONERA in an aircraft. The GIRAFE instrument was originally a research instrument, funded by the French Navy, aimed at marine gravimetry. This project therefore represented the first step in the evolution from a marine instrument to an airborne instrument.

Link to project page: https://doi.org/10.57780/esa-b0ed0a3

Publications

  • Jensen, T. E., Dale, B., Stokholm, A., Forsberg, R., Bresson, A., Zahzam, N., Bonnin, A., and Bidel, Y. (2025).Airborne gravimetry with quantum technology: observations from Iceland and Greenland, Earth Syst. Sci. Data17: 1667–1684, https://doi.org/10.5194/essd-17-1667-2025. 
  • Vu, D.T., Bonvalot, S., Seoane, L. et al.(2024). Potential of cold-atom airborne gravimetry to improve coastal gravity field and quasigeoid modelling. J Geod98: 28. https://doi.org/10.1007/s00190-024-01839-0
  • Bidel Y, Zahzam N, Bresson A, Blanchard C, Bonnin A, Bernard J, Cadoret M, Jensen TE, Forsberg R, Salaun C, Lucas S, Lequentrec-Lalancette MF, Rouxel D, Gabalda G, Seoane L, Vu DT, Bruinsma S, Bonvalot S (2023) Airborne absolute Gravimetry with a quantum sensor, comparison with classical technologies. J Geophys Res Solid Earth128(4):e2022JB025921. https://doi.org/10.1029/2022JB025921
  • Bidel, Y., Zahzam, N., Bresson, A. et al.(2020). Absolute airborne gravimetry with a cold atom sensor. J Geod94: 20. https://doi.org/10.1007/s00190-020-01350-2