Precession-Nutation Estimates from Optical Astrometry 1899.7–1992.0 and Comparison with VLBI Results

Abstract

AbstractThe most recent solution of Earth orientation parameters from the observations made by optical astrometry in 1899.7-1992.0 at 33 observatories is used to estimate the corrections of the present IAU model of precession-nutation. Since the resolution of the solution is about five days, only the terms with periods of 14 days and longer are considered. The results are compared with VLBI-based corrections of the standard precession-nutation model, and the differences are discussed.