EGU21-7827, updated on 24 May 2022
EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Effect of non-tidal station loading on Lunar Laser Ranging observatories and on the estimation of Earth orientation parameters

Vishwa Vijay Singh1,2, Liliane Biskupek1, Jürgen Müller1, and Mingyue Zhang1,3,4
Vishwa Vijay Singh et al.
  • 1Leibniz University Hannover, Institute of Geodesy, Department of Geodesy and Geoinformatics, Hannover, Germany (
  • 2Institute for Satellite Geodesy and Inertial Sensing, German Aerospace Center (DLR), Hannover, Germany (
  • 3State Key Laboratory of Geodesy and Earth’s Dynamics, Institute of Geodesy and Geophysics, APM, Chinese Academy of Sciences, Wuhan, China (
  • 4College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China (

The distance between the observatories on Earth and the retro-reflectors on the Moon has been regularly observed by the Lunar Laser Ranging (LLR) experiment since 1970. In the recent years, observations with bigger telescopes (APOLLO) and at infra-red wavelength (OCA) are carried out, resulting in a better distribution of precise LLR data over the lunar orbit and the observed retro-reflectors on the Moon, and a higher number of LLR observations in total. Providing the longest time series of any space geodetic technique for studying the Earth-Moon dynamics, LLR can also support the estimation of Earth orientation parameters (EOP), like UT1. The increased number of highly accurate LLR observations enables a more accurate estimation of the EOP. In this study, we add the effect of non-tidal station loading (NTSL) in the analysis of the LLR data, and determine post-fit residuals and EOP. The non-tidal loading datasets provided by the German Research Centre for Geosciences (GFZ), the International Mass Loading Service (IMLS), and the EOST loading service of University of Strasbourg in France are included as corrections to the coordinates of the LLR observatories, in addition to the standard corrections suggested by the International Earth Rotation and Reference Systems Service (IERS) 2010 conventions. The Earth surface deforms up to the centimetre level due to the effect of NTSL. By considering this effect in the Institute of Geodesy (IfE) LLR model (called ‘LUNAR’), we obtain a change in the uncertainties of the estimated station coordinates resulting in an up to 1% improvement, an improvement in the post-fit LLR residuals of up to 9%, and a decrease in the power of the annual signal in the LLR post-fit residuals of up to 57%. In a second part of the study, we investigate whether the modelling of NTSL leads to an improvement in the determination of EOP from LLR data. Recent results will be presented.

How to cite: Singh, V. V., Biskupek, L., Müller, J., and Zhang, M.: Effect of non-tidal station loading on Lunar Laser Ranging observatories and on the estimation of Earth orientation parameters, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7827,, 2021.