SCIENCE BACKGROUND

The Rotating Earth: Science Background

The parameters to describe the Earth's rotation and how its irregularities are measured.

The International Celestial Reference System and its realization, the International Celestial Reference Frame.

The International Terrestrial Reference System and its realization, the International Terrestrial Reference Frame.

Recommendations

IAU and IUGG resolutions and recommendations on reference systems and on the IERS.

Observation techniques

The observation techniques for earth rotation and reference systems: GPS, SLR, LLR, VLBI, and DORIS.

Publications on earth rotation, reference systems, geophysical fluids and on the IERS.