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Time and Frequency Transfer Activities at NIST



Victor S. Zhang, Michael A. Lombardi


The National Institute of Standards and Technology (NIST) maintains one of the world s most accurate and stable time scales, and also developed and maintains the primary frequency standard for the United States. Various techniques are used to compare the NIST time scale, UTC(NIST), and the NIST primary frequency standard to other standards located around the world. These techniques include two-way satellite time and frequency transfer (TWSTFT), code-based GPS common-view, and GPS carrier-phase comparisons. NIST provides remote time and frequency calibration services to industries and research institutes using GPS time transfer technologies. We disseminate UTC(NIST) through signals broadcast by our radio stations WWV/WWVH and WWVB, the Internet Time Service (ITS), and the Automated Computer Time Service (ACTS). NIST also conducts research intended to develop new time transfer techniques, and to improve the performance of existing methods.
Proceedings Title
Proc. 2008 PTTI Conf.
Conference Dates
December 1-4, 2008
Conference Location
Reston, VA
Conference Title
The Fortieth Annual Precise Time and Time Interval (PTTI) Systems and Applications Meeting


dissemination, frequency transfer, time transfer, traceability


Zhang, V. and Lombardi, M. (2008), Time and Frequency Transfer Activities at NIST, Proc. 2008 PTTI Conf., Reston, VA, [online], (Accessed May 21, 2024)


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Created December 1, 2008, Updated February 19, 2017