Comments on the effect of adopting new precession and equinox correctionsIt is shown that the derived terrestrial longitude zero point and UT1 rate will be different when determined by classical optical and space techniques so long as the precession constant and equinox offset and drift are imperfectly known. For the uncertainty of the new IAU precession constant, this inconsistency is expected to be nearly 0.04 arcsec in longitude and 0.1 ms/yr in UT1 rate. The consistency of constants does not guarantee consistent results. The classical practice of defining Greenwich Mean Sidereal Time (GMST) as invariant with respect to a fixed equinox if the longitude and UT1 results from the inertial techniques are to be stable against changes in the precession constant. One form for GMST is given.
Document ID
19820063665
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Williams, J. G. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Melbourne, W. G. (California Institute of Technology, Jet Propulsion Laboratory, Pasadena CA, United States)
Date Acquired
August 10, 2013
Publication Date
January 1, 1982
Subject Category
Astronomy
Meeting Information
Meeting: High-precision earth rotation and earth-moon dynamics: Lunar distances and related observations