Lunar-Based Measurements of the Moon’s Physical Libration: Methods and Accuracy Estimates

Computer simulation results are reported for planned lunar-based observations to be conducted using an automated zenith telescope that can be placed at any lunar latitude. Benefits of lunar-based observations are shown, in comparison with lunar laser ranging. It is investigated whether, and how effectively, these observations can be used to determine the lunar rotation parameters (physical libration). The accuracy requirements for these observations are analyzed in view of the accuracy requirements for determining the lunar rotation parameters. The necessary number of telescopes, as well as their optimal locations, is assessed.