Estimation of Earth Rotation Parameter UT1 from Lunar Laser Ranging Observations

AbstractSince 1969 Lunar Laser Ranging (LLR) data have been collected by different observatories and analysed by various analysis groups. LLR is providing the longest time series of any space geodetic technique for studying the Earth-Moon dynamics. In recent years, observations have been carried out with larger telescopes and at infra-red (IR) wavelength, resulting in a better distribution of precise LLR data over the lunar orbit and the observed retro-reflectors on the Moon. The increased number of high-accuracy observations allows for more accurate determination of Earth Orientation Parameters (EOPs) from LLR data compared to previous years. In this study we focus on ΔUT1 results from different constellations and compare our LLR solution to the IERS EOP C04 series.