Benefit of new high-precision llr data for the determination of relativistic parameters

authored by
Liliane Biskupek, Jürgen Müller, Jean Marie Torre

Since 1969, Lunar Laser Ranging (LLR) data have been collected by various observa-tories and analysed by different analysis groups. 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. This is a great advantage for various investigations in the LLR analysis. The aim of this study is to evaluate the benefit of the new LLR data for the determination of relativistic parame-ters. Here, we show current results for relativistic parameters like a possible temporal variation of the gravitational constant Ġ/G0 = (−5.0 ± 9.6) × 10−15 yr−1, the equivalence principle with ∆( mg /mi)EM= (−2.1±2.4)×10−14, and the PPN parameters β − 1 = (6.2 ± 7.2) × 10−5 and γ − 1 = (1.7 ± 1.6) × 10−4. The results show a significant improvement in the accuracy of the various parameters, mainly due to better coverage of the lunar orbit, better distribution of measurements over the lunar retro-reflectors, and last but not least, higher accuracy of the data. Within the estimated accuracies, no violation of Einstein’s theory is found and the results set improved limits for the different effects.

Institute of Geodesy
External Organisation(s)
Observatoire Côte d'Azur
Publication date
Publication status
Peer reviewed
ASJC Scopus subject areas
Physics and Astronomy(all)
Electronic version(s) (Access: Open) (Access: Open)