Estimation of the Lunar Physical Librations
Authors: Newhall, X.X.; Williams, J.G.
Source: Celestial Mechanics and Dynamical Astronomy, Volume 66, Number 1, 1996 , pp. 21-30(10)
Abstract:The recent long-term integration of JPL ephemeris DE403/LE403 yielded lunar physical librations covering 6000 years. A Fourier analysis of a 718-year subset of this span produced estimates of the component frequencies of the forced and free librations. A subsequent iterative least-squares estimation procedure provided precise values for phases and for time-varying amplitudes and frequencies. Two free libration modes were found; presence of a third is possible but close to the noise.
Document Type: Regular Paper
Affiliations: Jet Propulsion Laboratory, California Institute of Technology Pasadena, California, USA
Publication date: January 1, 1996