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 Directive 4650.05, 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 3.9 ns rms in 2009. The data used to generate UTC (USNO) are based upon 60 cesium and 24 hydrogen maser frequency standards in four buildings at two sites. USNO disseminates time via voice, telephone modem, LORAN, 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.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2009
Accession Number
ADA518041

Entities

People

  • Demetrios N. Matsakis

Organizations

  • United States Naval Observatory

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Accuracy
  • Algorithms
  • Artificial Satellites
  • Atomic Beam Masers
  • British Columbia
  • California
  • Clocks
  • Frequency
  • Frequency Standards
  • Jet Propulsion
  • Ku Band
  • Measurement
  • Navigation
  • Observatories
  • Standards
  • Time Intervals
  • United States

Readers

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

Technology Areas

  • Space