AA's Parent and Peer Organizations
Astronomical Applications Department (AA)
is one of five scientific departments within the
U.S. Naval Observatory
(USNO). The USNO
Echelon 4 command located organizationally under
Meteorology and Oceanography Command
U.S. Fleet Forces Command
(USFF), and the
of Naval Operations
The AA Department mission is described elsewhere.
The other scientific departments at the USNO are:
Celestial Reference Frame Department
The Celestial Reference Frame Department is responsible for the determination of the positions and
motions of stars and solar system objects and the establishment of celestial reference
frames. Advanced equipment and methods, such as large scale CCD measuring devices,
speckle and radio interferometry, are being used or developed to extend the accuracy
and brightness limits of the reference frames. The results of the observational
programs are published in Naval Observatory publications and in refereed journals, and
are made available in electronic formats.
Earth Orientation Department
(EO): The Earth Orientation Department determines and predicts the
time-varying alignment of the Earth's terrestrial reference frame with respect to the
celestial reference frame. The Earth Orientation Parameters (EOP) determined are the
coordinates of the Earth's pole (polar motion), the rotation angle about the pole
(Universal Time or UT1),
precession, and nutation. Observational results are published regularly.
The Flagstaff Station is USNO's dark-sky site. Its mission is to make, analyze, and
interpret such astrometric and photometric dark sky observations as are required to
fulfill the mission of the U.S. Naval Observatory, and to conduct a research program
to improve the observational methods and the accuracy of astronomical data required by
the Navy and other components of the Department of Defense.
Precise Time Department
(PT): The Precise Time Department serves as the official source of time
for the Department of Defense and for the Global Positioning System (GPS), and a
Standard of Time for the United States.