Estimation of Earth Rotation Parameter UT1 from Lunar Laser Ranging Observations

Abstract Since 1969 Lunar Laser Ranging (LLR) data have been collected by different observatories and analysed various analysis groups. LLR is providing the longest time series of any space geodetic technique for studying Earth-Moon dynamics. In recent years, observations carried out with larger telescopes at infra-red (IR) wavelength, resulting in a better distribution precise over lunar orbit observed retro-reflectors on Moon. The increased number high-accuracy allows more accurate determination Earth Orientation Parameters (EOPs) from compared to previous years. this study we focus Δ UT1 results constellations compare our solution IERS EOP C04 series.