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NIST time and frequency radio stations: WWV, WWVH, and WWVB



Glenn Nelson, Michael A. Lombardi, Windell Oskay


The National Institute of Standards and Technology (NIST) provides standard time and frequency information through three radio broadcast stations that are routinely used by millions of customers. The stations, WWV and WWVB, located in Fort Collins, Colorado, and WWVH, located on the island of Kauai in Hawaii, are the only radio stations located in the United States whose sole purposes are to distribute standard time and frequency information. This document provides a comprehensive look at the NIST time and frequency radio stations. It provides a physical and technical description of each station, and describes how the stations are operated by NIST. It also examines how the stations are used by their customers, and estimates the measurement uncertainties of the radio signals, both as transmitted by NIST and as received by customers.
Special Publication (NIST SP) - 250-67
Report Number


broadcast services, calibration, frequency, time interval, time-of-day


Nelson, G. , Lombardi, M. and Oskay, W. (2005), NIST time and frequency radio stations: WWV, WWVH, and WWVB, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online],, (Accessed July 25, 2024)


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Created December 31, 2004, Updated October 12, 2021