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

reportActive / Technical Report | Accession Number: ADA518041 | Open PDF

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, USNOs 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 httpwww.usno.navy.milUSNO.

Author(s):
Matsakis, Demetrios
Author Organization(s):
NAVAL OBSERVATORY WASHINGTON DC TIME SERVICE DIV
Descriptive Note:
Conference paper
Supplementary Note:
Presented at the Annual Precise Time and Time Interval (PTTI) Systems and Applications Meeting (41st), held on 16-19 Nov 2009, in Santa Ana Pueblo, NM. The original document contains color images.
Pagination:
0023

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_5_Command and Control; JCA_6.1_Information Transport; 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_1.2_Force Preparation; JCA_1_Force Support; JCA_3.2_Engagement; JCA_3_Force Application; JCA_8_Building Partnerships
Modernization Areas:
Space
Communities of Interest:
Space
Descriptor(s):
*TIME, *CLOCKS, NETWORKS, ACCURACY, FREQUENCY STANDARDS, PRECISION, INTERNATIONAL, TELEPHONE SYSTEMS, MASERS, LORAN, SYMPOSIA, UNITED STATES, GLOBAL POSITIONING SYSTEM
Field(s)/Group(s):
Test Facilities, Equipment and Methods
Keyword(s):
*MASTER CLOCK, NTP(NETWORK TIME PROTOCOL), TWSTT(TWO WAY SATELLITE TIME TRANSFER)
Report Date:
2009 Nov 01
Creation Date:
2010 Apr 28