TY - JOUR

T1 - Gravity field modelling for the Hannover 10 m atom interferometer

AU - Schilling, Manuel

AU - Wodey, Étienne

AU - Timmen, Ludger

AU - Tell, Dorothee

AU - Zipfel, Klaus H.

AU - Schlippert, Dennis

AU - Schubert, Christian

AU - Rasel, Ernst M.

AU - Müller, Jürgen

N1 - Funding Information: The Hannover Very Long Baseline Atom Interferometry facility is a major research equipment funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation). This work was supported by the DFG Collaborative Research Center 1128 “geo-Q” (Project A02, Contract Number 239994235) and is supported by the CRC 1227 “DQ-mat” (Project B07, Contract Number 274200144), Germany’s Excellence Strategy—EXC-2123 “QuantumFrontiers”—390837967, and the computing cluster of the Leibniz University Hannover under patronage of the Lower Saxony Ministry of Science and Culture (MWK) and the DFG. M. S., E. W., and C. S. acknowledge support from “Niedersächsisches Vorab” through the “Quantum- and Nano-Metrology (QUANOMET)” initiative (Project QT3), and for initial funding of research in the DLR-SI institute. D. S. acknowledges funding from the German Federal Ministry of Education and Research (BMBF) through the funding program Photonics Research Germany (Contract Number 13N14875). The VLBAI support structure was conceived by the engineering office Heinz Berlin (Wennigsen, Germany) in collaboration with the VLBAI science team, and produced by Aljo Aluminium-Bau Jonuscheit GmbH (Berne, Germany). We thank W. Ertmer for his vision and long-lasting support on very long baseline atom interferometry and the acquisition of funding for the Hannover Institute of Technology. We are grateful to T. Froböse and A. Wanner for their assistance during the installation of the vacuum tank and support structure. We thank the three reviewers for their valuable input to improve this article.

PY - 2020/11/27

Y1 - 2020/11/27

N2 - Absolute gravimeters are used in geodesy, geophysics and physics for a wide spectrum of applications. Stable gravimetric measurements over timescales from several days to decades are required to provide relevant insight into geophysical processes. Users of absolute gravimeters participate in comparisons with a metrological reference in order to monitor the temporal stability of the instruments and determine the bias to that reference. However, since no measurement standard of higher-order accuracy currently exists, users of absolute gravimeters participate in key comparisons led by the International Committee for Weights and Measures. These comparisons provide the reference values of highest accuracy compared to the calibration against a single gravimeter operated at a metrological institute. The construction of stationary, large-scale atom interferometers paves the way for a new measurement standard in absolute gravimetry used as a reference with a potential stability up to 1nm/s2 at 1 s integration time. At the Leibniz University Hannover, we are currently building such a very long baseline atom interferometer with a 10-m-long interaction zone. The knowledge of local gravity and its gradient along and around the baseline is required to establish the instrument’s uncertainty budget and enable transfers of gravimetric measurements to nearby devices for comparison and calibration purposes. We therefore established a control network for relative gravimeters and repeatedly measured its connections during the construction of the atom interferometer. We additionally developed a 3D model of the host building to investigate the self-attraction effect and studied the impact of mass changes due to groundwater hydrology on the gravity field around the reference instrument. The gravitational effect from the building 3D model is in excellent agreement with the latest gravimetric measurement campaign which opens the possibility to transfer gravity values with an uncertainty below the 10nm/s2 level.

AB - Absolute gravimeters are used in geodesy, geophysics and physics for a wide spectrum of applications. Stable gravimetric measurements over timescales from several days to decades are required to provide relevant insight into geophysical processes. Users of absolute gravimeters participate in comparisons with a metrological reference in order to monitor the temporal stability of the instruments and determine the bias to that reference. However, since no measurement standard of higher-order accuracy currently exists, users of absolute gravimeters participate in key comparisons led by the International Committee for Weights and Measures. These comparisons provide the reference values of highest accuracy compared to the calibration against a single gravimeter operated at a metrological institute. The construction of stationary, large-scale atom interferometers paves the way for a new measurement standard in absolute gravimetry used as a reference with a potential stability up to 1nm/s2 at 1 s integration time. At the Leibniz University Hannover, we are currently building such a very long baseline atom interferometer with a 10-m-long interaction zone. The knowledge of local gravity and its gradient along and around the baseline is required to establish the instrument’s uncertainty budget and enable transfers of gravimetric measurements to nearby devices for comparison and calibration purposes. We therefore established a control network for relative gravimeters and repeatedly measured its connections during the construction of the atom interferometer. We additionally developed a 3D model of the host building to investigate the self-attraction effect and studied the impact of mass changes due to groundwater hydrology on the gravity field around the reference instrument. The gravitational effect from the building 3D model is in excellent agreement with the latest gravimetric measurement campaign which opens the possibility to transfer gravity values with an uncertainty below the 10nm/s2 level.

KW - Absolute gravimetry

KW - Atom interferometry

KW - Gravimeter reference

KW - Gravity acceleration

UR - http://www.scopus.com/inward/record.url?scp=85096990155&partnerID=8YFLogxK

U2 - 10.1007/s00190-020-01451-y

DO - 10.1007/s00190-020-01451-y

M3 - Article

VL - 94

JO - Journal of Geodesy

JF - Journal of Geodesy

SN - 0949-7714

IS - 12

M1 - 122

ER -