Time and Frequency Activities at the U.S. Naval Observatory

Abstract

The U.S. Naval Observatory (USNO) has provided timing for the Navy since 1830 and via DoD Directives 4650.05 and 4650.07 is the sole source of timing for the Department of Defense. In cooperation with other institutions, the USNO also provides timing for the United States and the international community. Its Master Clock (MC) is the source of UTC (USNO), USNO's realization of Coordinated Universal Time (UTC), which has stayed within 5 ns rms of UTC since 1999 and within 2 ns rms in 2012. The data used to generate UTC (USNO) are based upon 87 cesium, 38 hydrogen maser, and 4 rubidium fountain frequency standards in several buildings at two sites. USNO disseminates time via voice, telephone modem, Network Time Protocol (NTP), GPS, and Two-Way Satellite Time Transfer (TWSTT). This paper describes some of the changes being made to meet the future needs for precision, accuracy, and robustness. Further details and explanations of our services can be found online at http://www.usno.navy.mil/USNO/time.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2012
Accession Number
ADA585806

Entities

People

  • Demetrios N. Matsakis

Organizations

  • United States Naval Observatory

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Accuracy
  • Algorithms
  • Artificial Satellites
  • Authentication
  • Calibration
  • Clocks
  • Computers
  • Denial Of Service Attack
  • Frequency
  • Frequency Standards
  • Information Operations
  • Jet Propulsion
  • Measurement
  • Observatories
  • Precision
  • Standards
  • Time Intervals

Readers

  • Positioning, Navigation, and Timing (PNT) Technology.

Technology Areas

  • Space