EGU2020-6220, updated on 05 Jan 2023
https://doi.org/10.5194/egusphere-egu2020-6220
EGU General Assembly 2020
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Geodetic determination of the gravitational potential difference for an optical lattice clock comparison in the Kanto region in Japan

Yoshiyuki Tanaka1, Yosuke Aoki2, and Ryuichi Nishiyama2
Yoshiyuki Tanaka et al.
  • 1University of Tokyo, Earth and Planetary Science, Tokyo, Japan (y-tanaka@eps.s.u-tokyo.ac.jp)
  • 2University of Tokyo, Earthquake Research Institute, Tokyo, Japan

Recent advancements in atomic clocks have enabled us to measure gravitational potential differences with a precision which is applicable to geodetic uses, based on the gravitational red shift. In Europe, international fiber networks linking optical clocks have been developed for promoting the unification of height reference systems across countries, and 10 cm-level agreements in terms of the equivalent height difference to the gravitational potential have been achieved in the comparisons between chronometric and classical geodetic methods. In Japan, similar comparisons using two optical lattice clocks were carried out for i) a 15-km fiber connecting RIKEN in Wako city and the Hongo campus of the University of Tokyo and ii) a 450-m fiber link which vertically connected the observatory and the ground at the Tokyo Skytree. For the former comparison, agreement between chronometric and geodetic results was better than 10 cm, and for the latter, data are under analysis. A new clock site has been developed at the NTT Basic Research Laboratories in Atsugi City. Clocks in Wako, Hongo and Atsugi constitute an approximately 100-km-scale network. In this presentation, we report a preliminary result on the geodetic leveling survey to determine the gravitational potential difference between these three sites. To estimate uncertainties in the potential difference, we will compare the result partially with those determined from the geoid model and the GNSS ellipsoidal height. We will also consider the effects of crustal vertical motion, in addition to measurement errors.

How to cite: Tanaka, Y., Aoki, Y., and Nishiyama, R.: Geodetic determination of the gravitational potential difference for an optical lattice clock comparison in the Kanto region in Japan, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-6220, https://doi.org/10.5194/egusphere-egu2020-6220, 2020.

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