Earth rotation equations containing both nutation and polar motion

Improvement of Nonrigid - Earth Nutation Theory by Adding a Model Free Core Nutation Term

Abstract. From the analysis of VLBI observational data compiled by USNO (U.S. Naval Observatory) from MJD 44089.994 to 51618.250 (McCarthy, 2000), we showed that a strong peak around 400 sidereal days in the spectrum of its di erences from the IERS96 nutation theory could be explained by adding a model Free Core Nutation (FCN) term in the form of a single damped oscillation. Then we developed a...

Transverse Navigation under the Ellipsoidal Earth Model and its Performance in both Polar and Non-polar areas

The transverse navigation system has been designed and developed to solve the challenges of navigation in polar regions. However, considerable theoretical errors are introduced into the system when the spherical Earth model is adopted. To tackle this problem, a transverse navigation mechanism under the ellipsoidal Earth model has been proposed in this research and the application regions of the...

Time Measurement and Earth Rotation

Earth Rotation Variations – Long Period

3.11.

On the Adoption of a Terrestrial Reference Frame

The report of the IAU Working Group on Nutation endorsed by Commissions 4, 8, 19 and 31 at the 1979 General Assembly points out that "... the complete theory of the general nutational motion of the Earth about its center of mass may be described by the sum of two components, astronomical nutation, commonly referred to as nutation, which is nutation with respect to a space-fixed coordinate syste...