Values computed using the IAU2000A
nutation theory and the IAU1976 precession theory with rate
corrections.
| Name |
Dimension |
Type |
Description |
| Time |
DateFormat |
Real Number |
Time. |
| MJD |
Unitless |
Real Number |
Modified Julian Date (UTC time scale). |
| UT1MJD |
Unitless |
Real Number |
Modified Julian Date (UT1 time scale). |
| X (Series) |
AngleUnit |
Real Number |
The X direction cosine of the CIP unit vector,
evaluated using the series expansion available from IERS Tech Note
32. For convenience, the value is expressed as if it were an
angle. |
| Y (Series) |
AngleUnit |
Real Number |
The Y direction cosine of the CIP unit vector,
evaluated using the series expansion available from IERS Tech Note
32. For convenience, the value is expressed as if it were an
angle. |
| S (Series) |
AngleUnit |
Real Number |
The CIO locator, evaluated using the series
expansion available from IERS Tech Note 32, and the values of X
(Series) and Y(Series). |
| X (Interpolated) |
AngleUnit |
Real Number |
The X direction cosine of the CIP unit vector,
evaluated using interpolation of a table of X values from
1975-2050. |
| Y (Interpolated) |
AngleUnit |
Real Number |
The Y direction cosine of the CIP unit vector,
evaluated using interpolation of a table of Y values from
1975-2050. |
| S (Interpolated) |
AngleUnit |
Real Number |
The CIO locator, evaluated using interpolation of a
table of S values from 1975-2050. |
| X (Delta Psi Eps) |
AngleUnit |
Real Number |
The X direction cosine of the CIP unit vector,
evaluated by computing the Bias Precession Nutation (BPN) matrix
using expressions dependent on Delta Psi and Delta Eps. |
| Y (Delta Psi Eps) |
AngleUnit |
Real Number |
The Y direction cosine of the CIP unit vector,
evaluated by computing the Bias Precession Nutation (BPN) matrix
using expressions dependent on Delta Psi and Delta Eps. |
| S (Delta Psi Eps) |
AngleUnit |
Real Number |
The CIO locator, evaluated using the series
expansion available from IERS Tech Note 32, and the values of X
(Delta Psi Eps) and Y(Delta Psi Eps). |
| X (Series - Interp) |
AngleUnit |
Real Number |
The difference between X (Series) and X
(Interpolated) values. |
| Y (Series - Interp) |
AngleUnit |
Real Number |
The difference between X (Series) and X
(Interpolated) values. |
| S (Series - Interp) |
AngleUnit |
Real Number |
The difference in S between that value computed
using the IERS series approximation minus the value found through
interpolation. |
| X (Delta Psi Eps - Interp) |
AngleUnit |
Real Number |
The difference between X (Delta Psi Eps) and X
(Interpolated) values. |
| Y (Delta Psi Eps - Interp) |
AngleUnit |
Real Number |
The difference between Y (Delta Psi Eps) and Y
(Interpolated) values. |
| S (Delta Psi Eps - Interp) |
AngleUnit |
Real Number |
The difference between S (Delta Psi Eps) and S
(Interpolated) values. |
| Angle Diff (Series -
Interp) |
AngleUnit |
Real Number |
The angular difference between the frames realized
using X, Y, S computed from the series expansion and X, Y, S
computed using interpolation. |
| Angle Diff (Delta Psi Eps
- Interp) |
AngleUnit |
Real Number |
The angular difference between the frames realized
using X, Y, S computed from the Delta Psi and Delta Eps and X, Y, S
computed using interpolation. |
| Delta Psi |
AngleUnit |
Real Number |
Variable associated with the definition of the
IAU2000A nutation theory. |
| Delta Eps |
AngleUnit |
Real Number |
Variable associated with the definition of the
IAU2000A nutation theory. |
| Earth Rotation
Angle |
AngleUnit |
Real Number |
The rotation along the intermediate equator between
the CIO and terrestrial origin. |
| dX |
AngleUnit |
Real Number |
The correction to X when using the ICRF theory.
Published as part of EOP data. |
| dY |
AngleUnit |
Real Number |
The correction to Y when using the ICRF theory.
Published as part of EOP data. |
| Delta Delta Psi |
AngleUnit |
Real Number |
The correction to Delta Psi for converting between
J2000 and the ICRF reference frame using the FK5 IAU76 theory.
Published as part of EOP data. |
| Delta Delta Eps |
AngleUnit |
Real Number |
The correction to Delta Epsilon for converting
between J2000 and the ICRF reference frame using the FK5 IAU76
theory. Published as part of EOP data. |
| Pole Wander X |
AngleUnit |
Real Number |
Small angle related to changes in orientation of
the earth pole due to continental drift. |
| Pole Wander Y |
AngleUnit |
Real Number |
Small angle related to changes in orientation of
the earth pole due to continental drift. |
| UT1-UTC |
TimeUnit |
Real Number |
The difference between Universal Time (UT1) and
Coordinated Universal Time (UTC). |
| TDTTimeSinceJ2000 |
TimeUnit |
Real Number |
Duration (in TDT seconds) since the J2000
epoch. |
| UT1TimeSinceJ2000 |
TimeUnit |
Real Number |
Duration (in UT1 seconds) since the J2000
epoch |
| TDTMinusUT1 |
TimeUnit |
Real Number |
The difference between TDTTimeSinceJ2000 and
UT1TimeSinceJ2000. |