Traceability in Time and Frequency Metrology

Abstract

This paper discusses the techniques and reference signals used to establish traceability to national and international standards when making time and tlequency measurements. It explains how traceable time and frequency tiormation is distributed by NIST and other national metrology institutes through radio, telephone, and Internet signals. It also describes how signals broadcast by the Global Positioning System (GPS) satellites can serve as a traceable time and frequency reference that is available worldwide.