Results from lunar laser ranging data analysis

Abstract

The lunar laser range data taken at McDonald Observatory between Aug. 1969 and May 1980 has been analyzed. The simple rms residual for the 2954 ranges is 31 cm. Results of the analysis include GM(earth) = 398600.45 cu km/sec sq within 0.02 cu km/sec sq and a secular acceleration of the lunar orbital mean longitude of -23.8 arcsec/sq century within 1.5 arcsec, which yields a Q of 12.3 at semidiurnal frequencies. The lunar harmonic C30 is -8.7/1,000,000 within 0.000001 and the lunar rotational dissipation of 0.0047 within 0.0005 day. Also resulting from the solution are geocentric coordinates of McDonald accurate to 30 cm, including the first value for the longitude with the new IAU constants and a dynamical equinox.