Rotation of the Earth from Lunar Laser Ranging

Abstract

We have extended our estimates of variation of latitude and UTO from the McDonald Observatory lunar laser ranging (LLR) observations to span the period October 1970 to November 1980. The typical formal uncertainties of our values are about 6 milliarcseconds (mas) and 0.5 milliseconds (ms) of time, respectively. We have compared our values of variation of latitude with those derived from the smoothed Circular D pole positions published by the Bureau International de l’Heure. The root-mean-square (rms) difference about the mean difference is 14 mas. A comparison of our smoothed UTO estimates with those calculated from the smoothed Circular D values of UT1 and pole position gives a corresponding rms difference of 1.5 ms. For the period covered by the MERIT Short Campaign, we have also compared our smoothed UTO values with (unsmoothed) ones derived from daily UT1 and pole-position values obtained by the Goddard Space Flight Center / Massachusetts Institute of Technology / Haystack Observatory group from very-long-baseline interferometric observations spanning two oneweek periods. The rms difference about the mean difference is 0.3 ms.KeywordsPole PositionRoyal Greenwich ObservatoryLunar Laser RangeDaily EstimateEarth Rotation ParameterThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.