岁差和章动

日长变化是表征地球自转运动的一个重要参数，它与极移、岁差和章动统称为地球定向参数（EOP）。

Length of Day ( LOD ) change is an important parameter which reflects the earth rotation . LOD change 、 Polar Motion ( PM )、 Precession and Nutation are called Earth Orientation Parameters ( EOP ) .

本文从爱因斯坦场方程的解开始，严格而细致地论证了相对论岁差和章动的起源，推导了测地、Lense-Thirring、Thomas岁差章动和黄极的相对论进动的理论表达式。

Beginning with the solution of the Einstein 's Field equation , this paper rigorously and intensively discusses the origin of the relativistic precession and nutation , and derives the theoretical expression of the geodetic 、 Lense-Thirring , Thomas precession , nutation and the relativistic advance of the ecliptic pole .

由此对CIP轴进行了理论定义，并给出了其极移、岁差和章动的动力学方程。

Therefore , the theoretical definition of CIP and its dynamical equation on polar motion and precession-nutation have been given .

地球自转运动包括岁差和章动，极移和日长的变化。

The rotation of the Earth includes precession , nutation , variations of the rotation rate and polar motion .