The institute of geodesy in the cluster of excellence QUEST
The Centre for Quantum Engineering and Space-Time Research (QUEST) is investigating the application of latest technologies in quantum physics for precise measurements. Novel sensors such as laser interferometers, atomic gravimeters or atomic clocks facilitate an improvement of the measurements by several orders of magnitude. This provides new possibilities and challenges for future observations in many scientific disciplines.
Geodetic projects within QUEST study the potential of novel instruments and develop first concepts for the observations. The analysis of selected space techniques is also elaborated to make use of the new accuracies. A better modeling of lunar laser ranging enables an investigation of the possible variation in the gravitational constant and the equivalence principle. External clock information is successfully added to GNSS receivers in collaboration with PTB. This provides a tool to separate the error sources and to improve the static and kinematic positioning. A quantum gravimeter is designed, which might overcome limitations of classical instruments with respect to resolution, sensor drift and spectral behavior in the near future.
One focus of geodetic applications in QUEST is the determination of the global gravity field of the Earth by satellite missions such as GRACE and GOCE and their followers. The measurements of the current missions are re-analyzed to improve the modeling of the time variable gravity field and to detect artificial signals of the sensors. Time series of the sensor data are investigated to recognize and calibrate the systems, which will also influence the design of the next missions.
New satellite instruments are developed to achieve better resolution in the next missions. An interferometric laser ranging system will determine the distances in nanometer precision between the GRACE follow-on satellites, whose launch is planned for 2016. Other innovations for future space missions are a multi-channel interferometry gradiometer to observe gravity field functionals in different directions or ultra-precise atomic clocks to measure gravity potential differences in the orbit. Transportable atomic clocks are also developed for measurements on the ground, which enable the direct observation of the gravitational potential differences as a new kind of geodetic signal.
The following institutes participate in QUEST:
- Institute of Quantum Optics, Leibniz University Hannover
- Institute for Gravitational Physics Leibniz University Hannover
- Institute of Theoretical Physics, Leibniz University Hannover
- Institute of Solid State Physics, Leibniz University Hannover
- Institute of Geodesy
- Institute of Applied Mathematics, Leibniz University Hannover.
- Laser Zentrum Hannover e.V. (LZH), Hannover
- Gravitational Wave Detektor GEO600
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig
- Center of Applied Technology and Microgravity (ZARM), Bremen
The institutes also cooperate with
- Institut fracilien de recherche sur les atomes froids (I.F.R.A.F.)
- Australian Research Council Centre of Excellence for Quantum-Atom Optics (ACQAO)
- University of Texas at Austin, Center for Space Research
- Aarhus University, Department of Physics and Astronomy