U.S. Naval Observatory Earth Orientation Department

Here you can obtain information on the past, current, and predicted future orientation of the Earth in space. The available Earth Orientation Parameters (EOP) include the coordinates of the Earth's pole (polar motion), the rotation angle about the pole (Universal Time or UT1), and celestial pole offsets (precession and nutation). Here you will also find the positions of the extragalactic radio sources which form the basis for the quasi-inertial celestial reference frame within which the EOP parameters are determined.

Earth Orientation Parameters:

Celestial Reference Frame:

GPS Data Analysis:

Other useful information:

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Last modified: 24 July 2009 Approved by EO Dept. Head, USNO