Update on Time and Frequency Activities at Nist

The mission and organization of the Time and Frequency Division of the National Institute of Standards and Technology (NIST) are reviewed and a discussion is presented of recent activities. Among the major recent milestones have been the development of cold-atom frequency standards, including the construction of a new cesium-fountain >equency standard and the design of a standard for operation on the International Space Station. In addition, the use of GPS carrier phase for frequency transfer at the Ix1 O-Ii level has been demonstrated, and the power radiated by WWVB has been increased to 50 kW. Other areas discussed include time scales, time transfer, optical pequency standards, and time andfiequency dissemination services.