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

reportActive / Technical Report | Accession Number: ADA580021 | Open PDF

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 UTCUSNO, USNO s realization of Coordinated Universal Time UTC, which has stayed within 5 ns rms of UTC since 1999 and within 4 ns rms in 2011. The data used to generate UTCUSNO are based upon 87 cesium, 38 hydrogen maser, and now also 4 rubidium fountain frequency standards in four 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.

Author(s):
Matsakis, Demetrios
Author Organization(s):
NAVAL OBSERVATORY WASHINGTON DC TIME SERVICE DIV
Descriptive Note:
Conference paper
Supplementary Note:
Presented at the 43rd Annual Precise Time and Time Interval (PTTI) Systems and Applications Meeting. Published in Proceedings of the 43rd Annual Precise Time and Time Interval (PTTI) Systems and Applications Meeting, p107-124, 2011.The original document contains color images.
Pagination:
0019

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release
Distribution Statement:
Approved For Public Release; Distribution Is Unlimited.

RECORD

Collection: TR
Identifying Numbers
Monitor Series:
USNO-TS
 Subject Terms
Joint Capability Areas:
JCA_6_Net Centric; JCA_6.4.1_Secure Information Exchange; JCA_4.6.1_General Engineering; JCA_4.6_Engineering; JCA_6.1.3_Switching and Routing; JCA_6.1.1_Wired Transmission; JCA_6.1_Information Transport; JCA_5_Command and Control; JCA_6.4_Information Assurance; JCA_5.2.3_Share Knowledge and Situational Awareness; JCA_5.2_Understand; JCA_5.3_Planning; JCA_4.3_Maintain; JCA_3.2_Engagement; JCA_3_Force Application; JCA_6.2.1_Information Sharing; JCA_6.2.2_Computing Services; JCA_8_Building Partnerships
Communities of Interest:
Space
Descriptor(s):
*CLOCKS, *TIME, ACCURACY, ARTIFICIAL SATELLITES, CESIUM, FREQUENCY STANDARDS, GLOBAL POSITIONING SYSTEM, HYDROGEN, MASERS, RUBIDIUM, STABILITY, SYMPOSIA
Field(s)/Group(s):
Test Facilities, Equipment and Methods
Keyword(s):
MC(MASTER CLOCK), UTC(COORDINATED UNIVERSAL TIME), NTP(NETWORK TIME PROTOCOL), TWSTT(TWO WAY SATELLITE TIME TRANSFER)
Report Date:
2010 Jan 01
Creation Date:
2013 Jul 24