Values computed using the IAU2000A theory for nutation (as adjusted) and the P03 theory of precession.
| 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 Notes 32 and 36. 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 Notes 32 and 36. 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 Notes 32 and 36, 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. |
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