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The Earth Orientation Parameter (EOP) are the other important parameters of the combined solution next to the station coordinates.

VLBI is the only geodetic space technique providing a full set of EOP's:



- pole coordinates (X- and Y-pole) and rates

- UT1-UTC (dUT1)

- LOD (Length of Day)

- nutation parameters dX and dY


For the ITRF2014 all parameters of the combined normal equations are transformed to 12h UT to bring it together with other geodetic space techniques.

The WRMS of the differences between the individual solution and the combined solution shows for X-Pole and Y-Pole a value between 40 and 100µas, for dUT1 between 5 and 15µs, for X-Pole and Y-Pole rates between 100 and 250µas/d, for LOD between 5 and 15µs/d and for the nutation dX and dY between 30 and 80µas.

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