WARNING: The expressions below describe a prediction formulation
that is not recommended for operational use. The expressions will
continue to be provided in order to allow users to implement legacy
procedures. Users are encouraged to explore the possibility of
utilizing the tabular predictions available in the bulletin or in
electronic data files available from the IERS Rapid Service/Prediction
Center located at USNO.
Because of the lower quality of this model, the prediction accuracy
is a few mas to tens of mas worse than the published accuracy of the
prediction model.
x = 0.1042 + 0.0809 cos A - 0.0636 sin A + 0.0229 cos C - 0.0156 sin C
y = 0.3713 - 0.0593 cos A - 0.0798 sin A - 0.0156 cos C - 0.0229 sin C
UT1-UTC = -0.3259 - 0.00138 (MJD - 57689) - (UT2-UT1)
where A = 2*pi*(MJD-57681)/365.25 and C = 2*pi*(MJD-57681)/435.