Departure Point, Earth’s Rate of Rotation and Coordinate Transformation in Quasi-Inertial Geocentric Equatorial Coordinate System (QIGECS)

Abstract

The paper summarizes the discussion on the origin of right-ascension and puts forward new arguments in view of high-precision Geodesy and Astrometry. From the movement of the Celestial Departure Point, the classical right-ascension precession might be amended by an additional term -0.^S000257/century originating from the nutation-precession interaction movement. A similar term might also be introduced in the maintenance of a terrestrial reference system, while the concept of a Terrestrial Departure Point is considered. The definition of the Earth’s rate of rotation in an inertial or quasi-inertial system is reviewed. A periodic erroneous term of maximum amplitude 2.65mas is pointed out in the conventional transfer relation between CRS and TRS, that can for its main part be compensated by introducing the periodic terms of Woolard’s equation of the equinox.