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 = 0.0989 - 0.0737 cos A + 0.0683 sin A + 0.0432 cos C + 0.0231 sin C
y = 0.3511 + 0.0624 cos A + 0.0697 sin A + 0.0231 cos C - 0.0432 sin C
UT1-UTC = -0.1994 - 0.00100 (MJD - 56772) - (UT2-UT1)
where A = 2*pi*(MJD-56764)/365.25 and C = 2*pi*(MJD-56764)/435.