Data Products

IERS Bulletin A (The National Earth Orientation Service Bulletin)

The Bulletin A Web Page

The most recent Earth Orientation Parameters (x, y, and UT1-UTC)

The Radio Optical Reference Frame (RORF)

The Radio Reference Frame Image Database (RRFID)

The Optical Image Database (OID)

Obtaining NEOS VLBI data

The Explanatory Supplement to IERS Bulletins A and B

Historical differences between International Atomic Time (TAI) and Coordinated Universal Time (UTC)

What is Earth Orientation?

What is a leap second?

Would you like to regularly receive EOP data? If so, please fill out and submit a product request form (requires a 'forms' capable browser).

Programs

Earth Orientation Parameters (EOP) analysis and prediction;

Global Positioning System (GPS) data analysis;

the Radio Reference Frame; and

Very Long Baseline Interferometry (VLBI) data analysis.

The Washington Correlator (WACO)

Publications

Recent staff publications

Miscellaneous

United States Naval Observatory (USNO)

International Astronomical Union (IAU)

IAU Commission 19: Rotation of the Earth

International Earth Rotation Service (IERS)

International Celestial Reference Frame (ICRF)

International Terrestrial Reference Frame (ITRF)

IERS Analysis Campaign to Investigate Motions of the Geocenter

IERS Sub-bureau for Rapid Service and Predictions

International VLBI Service (IVS)

National Earth Orientation Service (NEOS)

VLBI Group of NASA's Space Geodesy Program

International GPS Service (IGS)

IGS/BIPM Pilot Project to Study Accurate Time and Frequency Comparisons Using GPS Phase and Code Measurements