Earth Orientation Parameters

The Earth Orientation Parameters as measured by VLBI: X and Y pole positions and rates, UT1 angle and rate, and daily offsets in the nutation in longitude and obliquity were estimated for each session separately.

Plot of pole position X vs Y over time:

Note: if you wish to replay the animation for the above image, try right-clicking on the image and choosing "Show Controls" and/or "Play" (options vary by browser).


EOP time series: X pole, Ypole, UT1-UTC:


Nutation offset time series:


The VLBI-derived EOP time series that are output from the global solution can be downloaded on the Quarterly Solutions page. 

Final USNO EOP products which include additional processing can be found here.