Measurement of lunar libration based on lunar laser ranging

Abstract

Lunar laser ranging (LLR) data have been extensively utilized in fundamental physics research, yielding significant and fruitful outcomes. These data hold promising potential for advancing our understanding of lunar libration. In this study, we address the challenges associated with lunar libration analysis by employing data from multiple corner reflector arrays collected over a single night, thereby utilizing a shorter time interval. We conduct a comprehensive analysis of the uncertainty associated with each corner reflector array and establish a relational model between this uncertainty and lunar libration. This approach enables the measurement of lunar libration through the uncertainty inherent in LLR data. For our calculations, we utilized a combination of different corner reflector arrays, with data sourced from the Grasse Station. Our findings reveal that the lunar libration measurements obtained using the combinations of A11+A15 and A14+A15 are 2.473° (latitude), 2.470° (longitude), and -1.607° (latitude), -5.369° (longitude) respectively. The corresponding errors for these combinations are -0.302° (latitude), -0.272° (longitude), -0.193° (latitude), and -0.278° (longitude). These results underscore the efficacy of our methodology in accurately determining lunar libration through the analysis of LLR data uncertainties.