title: The SIM Time Network.
abstract: The Sistema Interamericano de Metrologia (SIM) is a regional metrology organization (RMO) whose members are the national metrology institutes (NMIs) located in the 34 nations of the Organization of American States (OAS). The SIM/OAS region extends throughout North, Central, and South America and the Caribbean Islands. About half of the SIM NMIs maintain national standards of time and frequency and must participate in international comparisons in order to establish metrological traceability to the International System (SI) of units. The SIM time network (SIMTN) was developed as a practical, cost effective, and technically sound way to automate these comparisons. The SIMTN continuously compares the time standards of SIM NMIs and produces measurement results in near real-time by utilizing the Internet and the Global Positioning System (GPS). Fifteen SIM NMIs have joined the network as of December 2010. This paper provides a brief overview of SIM and a technical description of the SIMTN. It presents international comparison results and examines the measurement uncertainties. It also discusses the metrological benefits that the network provides to its participants.
authors.affiliation: National Institute of Standards and Technology (NIST), Boulder, CO 80305, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Lombardi
authors.affiliation: National Institute of Standards and Technology (NIST), Boulder, CO 80305, USA.
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Novick
authors.affiliation: Centro Nacional de Metrologia (CENAM), Querétaro, Mexico.
authors.forename: J Mauricio
authors.initials: JM
authors.lastname: Lopez R
authors.affiliation: Centro Nacional de Metrologia (CENAM), Querétaro, Mexico.
authors.forename: Francisco
authors.initials: F
authors.lastname: Jimenez
authors.affiliation: Centro Nacional de Metrologia (CENAM), Querétaro, Mexico.
authors.forename: Eduardo
authors.initials: E
authors.lastname: de Carlos Lopez
authors.affiliation: National Research Council (NRC), Ottawa, Canada.
authors.forename: Jean-Simon
authors.initials: JS
authors.lastname: Boulanger
authors.affiliation: National Research Council (NRC), Ottawa, Canada.
authors.forename: Raymond
authors.initials: R
authors.lastname: Pelletier
authors.affiliation: National Observatory (ONRJ), Rio de Janeiro, Brazil.
authors.forename: Ricardo J
authors.initials: RJ
authors.lastname: de Carvalho
authors.affiliation: Centro Nacional de Metrologia de Panama (CENAMEP), Panama City, Panama.
authors.forename: Raul
authors.initials: R
authors.lastname: Solis
authors.affiliation: Instituto Costarricense de Electricidad (ICE), San Jose, Costa Rica.
authors.forename: Harold
authors.initials: H
authors.lastname: Sanchez
authors.affiliation: Superintendencia de Industria y Comercio (SIC), Bogota, Colombia.
authors.forename: Carlos Andres
authors.initials: CA
authors.lastname: Quevedo
authors.affiliation: Bureau of Standards Jamaica (BSJ), Kingston, Jamaica.
authors.forename: Gregory
authors.initials: G
authors.lastname: Pascoe
authors.affiliation: Instituto Nacional de Tecnologia Industrial (INTI), Buenos Aires, Argentina.
authors.forename: Daniel
authors.initials: D
authors.lastname: Perez
authors.affiliation: Laboratorio Nacional de Metrologia (LNM), Guatemala City, Guatemala.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bances
authors.affiliation: Administracion Nacional De Usinas Y Trasmisiones Electricas (UTE), Montevideo, Uruguay.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Trigo
authors.affiliation: Instituto Nacional de Tecnologia Normalizacion y Metrologia (INTN), Asuncion, Paraguay.
authors.forename: Victor
authors.initials: V
authors.lastname: Masi
authors.affiliation: Servicio Nacional de Metrologia (SNM), INDECOPI, Lima, Peru.
authors.forename: Henry
authors.initials: H
authors.lastname: Postigo
authors.affiliation: Trinidad and Tobago Bureau of Standards (TTBS), Trinidad and Tobago.
authors.forename: Anthony
authors.initials: A
authors.lastname: Questelles
authors.affiliation: Saint Lucia Bureau of Standards (SLBS), Castries, Saint Lucia.
authors.forename: Anselm
authors.initials: A
authors.lastname: Gittens
keywords: Internet; frequency; regional metrology organization; time; traceability