a factor-of-100,000 frequency range;

  • The narrowest linewidth laser for precision frequency measurement;

  • The unique mercury ion and logic clocks; and

  • The best capability for the phase noise measurement of microwave and millimeter-wave sources.

This range of assets and experiments leads to unique scientific by-products, such as improvements by a factor of 10 in setting limits on the possible time variations in fundamental constants, and the most accurate tests of special and general relativity.

NIST provides an array of services to a very broad user community in the United States: the NIST Internet Time Service is used more than 2.5 billion times every day; NIST radio station WWVB is widely used to synchronize commercial timekeeping devices to NIST time; the NIST Automated Computer Time Service helps industry meet Securities and Exchange Commission requirements to synchronize the time-stamping of hundreds of billions of dollars of electronic financial transactions to NIST time.

The following international projects are noted as excellent examples of building goodwill for the United States:

  • The NIST-led project of developing an international network of common-view GPS receivers will enable time and frequency comparisons throughout the Inter-American Metrology System (SIM), which covers North, South, and Central America. Eventually, continuous comparisons will be enabled between the United States, Canada, Mexico, Argentina, Brazil, Costa Rica, Jamaica, Panama, Uruguay, and perhaps several other SIM member nations (already operational for the countries identified). This project was funded by the Department of State.

  • The NIST-developed Satellite Time Service for the North African and Middle Eastern region in a joint venture with the National Institute of Standards of Egypt. This project is sponsored by the U.S.-Egypt Joint Board on Scientific and Technological Cooperation.


The division has done an excellent job of anticipating staffing needs by supporting students and postdoctoral researchers to participate in its projects. This approach provides a pool of trained talent, from which a large number of researchers continue employment at NIST. The work in this division is highly specialized, because time and frequency is a niche technology. Thus, specially trained staff are required to carry out the needed research. This need is generally met by a competent staff and a large contingent of visiting researchers, students, and postdoctoral fellows. The latter group typically is a major pool for the future staffing of the division.

There has been notable improvement in the ability of the division to use guest scientists. A highly effective program in Boulder enables both foreign and domestic scientists to work at NIST Boulder on contract through a new scientific services company. Programs through several universities in Colorado enable collaborative work by foreign and domestic scientists with the division.

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