Ms. Merri Sue Carter, Director

Tel: +1 202 762 1434

WDC for Rotation of the Earth
U.S. Naval Observatory

Fax: +1 202 762 1563

3450 Mass Ave., NW

U.S.A.

Maintained by: The Earth Orientation Parameters Division of the Time Service Department, U.S. Naval Observatory.

Summary of Data Held:
Earth rotation data: Rotation rate data (1933 to present), and polar motion data (1894 to present).
Astronomical observations: Latitude and longitude observations with photographic zenith tubes, transit instruments, moon-position cameras, astrolabes and interferometers.
Satellite data: Laser ranging data for the Moon and LAGEOS satellite.
Other: Doppler and VLBI data.

User Services: Open to visitors during normal working hours and Monday evenings. Advanced notice is required. Current data are available on the NEOS electronic bulletin board system. The system operates at 2400 baud, 8 data bits, 1 stop, no parity. The telephone number is +1 202 653 0597.

Publications: IERS Bulletin A, almanacs, circulars, Time Service Announce-ments, and the IERS Annual Report.