Principle of the Determination of the Free Librations of the Moon by Means of the LLR Method

In this paper, under the physicallidea that the tree librations of the Moon are taken to be the additional oscillations of the forced librations, the partial derivatives of the time delay τ_o in the theory of lunar laser ranging with respect to the parameters of the free librations by means of the mathematical means of the transformation of Jacobian, thereby giving the principle of the determination of the free librations of the Moon according to the LLR method.