Clock networks for height system unification

A simulation study

authored by: Hu Wu, Jürgen Müller, Claus Lämmerzahl
Abstract: The unification of local height systems has been a classical geodetic problem for a long time, the main challenges of which are the estimation of offsets between different height systems and the correction of tilts along the levelling lines. It has been proposed to address these challenges with clock networks. The latest generation of optical clocks as well as the dedicated frequency links, for example optical fibres, are now approaching to deliver the comparison of frequencies at the level of 1.0 × 10 -18. It corresponds to an accuracy of about 1.0 cm in height difference. Clock networks can thus serve as a powerful tool to connect local height systems. To verify the idea, we carried out simulations using the EUVN/2000 (European Unified Vertical Network) as apriori input. Four local height systems were simulated from the EUVN/2000 by introducing individual offsets and tilts, and were reunified by using measurements in clock networks. The results demonstrate the great potential of clock networks for height system unification. In case that the offsets between different height systems and tilts along national levelling lines in both longitudinal and latitudinal directions are considered, three or four clocks measurements for each local region are sufficient for the unification. These clocks are to be interconnected and should be properly arranged so that they can sense the levelling tilts where necessary. Our results also indicate that even clocks with one magnitude poorer accuracy than the desired ones can still unify the height systems to some extent, but it may cause a shift for the reunified system.
Organisation(s): Institute of Geodesy
QuantumFrontiers
External Organisation(s): Center of Applied Space Technology and Microgravity (ZARM)
Type: Article
Journal: Geophysical journal international
Volume: 216
Pages: 1594-1607
No. of pages: 14
ISSN: 0956-540X
Publication date: 28.11.2018
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Geophysics, Geochemistry and Petrology
Electronic version(s): https://doi.org/10.1093/gji/ggy508 (Access: Closed)

BibTeX

@article{68fb3059de0546f3acc92f8ced119937,
title = "Clock networks for height system unification: A simulation study",
abstract = "The unification of local height systems has been a classical geodetic problem for a long time, the main challenges of which are the estimation of offsets between different height systems and the correction of tilts along the levelling lines. It has been proposed to address these challenges with clock networks. The latest generation of optical clocks as well as the dedicated frequency links, for example optical fibres, are now approaching to deliver the comparison of frequencies at the level of 1.0 × 10 -18. It corresponds to an accuracy of about 1.0 cm in height difference. Clock networks can thus serve as a powerful tool to connect local height systems. To verify the idea, we carried out simulations using the EUVN/2000 (European Unified Vertical Network) as apriori input. Four local height systems were simulated from the EUVN/2000 by introducing individual offsets and tilts, and were reunified by using measurements in clock networks. The results demonstrate the great potential of clock networks for height system unification. In case that the offsets between different height systems and tilts along national levelling lines in both longitudinal and latitudinal directions are considered, three or four clocks measurements for each local region are sufficient for the unification. These clocks are to be interconnected and should be properly arranged so that they can sense the levelling tilts where necessary. Our results also indicate that even clocks with one magnitude poorer accuracy than the desired ones can still unify the height systems to some extent, but it may cause a shift for the reunified system.",
keywords = "Geodetic instrumentation, Geopotential theory, Reference systems, Satellite geodesy",
author = "Hu Wu and J{\"u}rgen M{\"u}ller and Claus L{\"a}mmerzahl",
note = "Funding Information: The authors thank the DFG Sonderforschungsbereich (SFB) 1128 {\textquoteleft}Relativistic Geodesy and Gravimetry with Quantum Sensors (geo-Q){\textquoteright} for financial support. Hu Wu acknowledges the International Space Science Institute (ISSI) for providing the opportunity to present this work at the Workshop on “Spacetime Metrology, Clocks and Relativistic Geodesy”, March 19-23, 2018. We also gratefully thank the two anonymous reviewers whose comments helped to improve and clarify this manuscript. Publisher Copyright: {\textcopyright} The Author(s) 2018. Published by Oxford University Press on behalf of The Royal Astronomical Society. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.",
year = "2018",
month = nov,
day = "28",
doi = "10.1093/gji/ggy508",
language = "English",
volume = "216",
pages = "1594--1607",
journal = "Geophysical journal international",
issn = "0956-540X",
publisher = "Oxford University Press",
number = "3",
}