Role of lunar laser ranging in realization of terrestrial, lunar, and ephemeris reference frames

TL;DR

This paper explores how lunar laser ranging can improve space geodesy by determining Earth and lunar orientation parameters and linking ephemeris frames to the ICRF, using extensive observational data and comparisons.

Contribution

It provides a comprehensive analysis of lunar laser ranging applications for space geodesy, including comparisons of different tie methods and models, with extensive observational data.

Findings

Lunar laser ranging can determine Earth orientation parameters.

It can help refine lunar rotational ephemeris.

It enables tying ephemeris frames to the ICRF.

Abstract

Three possible applications of lunar laser ranging to space geodesy are studied. First, the determination of daily Earth orientation parameters (UT0 and variation of latitude), which is rarely used nowadays in presence of all-year VLBI, SLR, and GNSS data. The second application is the determination of two (out of three) lunar orientation parameters, i.e. daily corrections to the rotational ephemeris of the Moon. It may be of importance for the future lunar satellite-based navigational systems. The third application is the tie of ephemeris frame (BCRF) to the ICRF. It has been studied before, though in this work it is extensively compared to another realization of the same tie, obtained by spacecraft VLBI observations; also, two different EOP series and two different models of tidal variations of geopotential are applied, with different outcomes on the tie. The EPM lunar-planetary ephemeris, along with its underlying dynamical model and software, was used to obtain the presented results. All available observations were processed, since the earliest made at the end of 1969 at the McDonald observatory till the end of July 2019 (Matera, Grasse and also Wettzell observatory which began to provide data in 2018). The results and some open questions are discussed.