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Time Coordination Throughout the Americas via the SIM Common-View GPS Network



Michael A. Lombardi, Andrew N. Novick, Jose M. Lopez, Jean-Simon Boulanger, Carlos Donado


The Sistema Interamericano de Metrologia (SIM) consists of national metrology institutes (NMIs) located in all 34 member nations of the Organization of American States (OAS), which extends throughout North, Central, and South America, and the Caribbean region. SIM is one of the world¿s five major regional metrology organizations (RMOs) recognized by the Bureau International des Poids et Mesures (BIPM). As the number and the quality of time and frequency standards in the SIM region has increased, it has become more important for SIM nations to be able to compare their standards to each other. To help advance the state of metrology in the SIM region and to get as many laboratories involved in international time coordination as possible, we have developed a network that provides continuous, near real time comparisons between the national time and frequency standards located in the SIM region. The network was designed to be low cost and easy to operate, but still capable of providing measurement uncertainties small enough to characterize the best standards in the SIM region. We present the results of comparisons conducted between four participating laboratories: NRC (Canada), NIST (USA), CENAM (Mexico) and CENAMEP (Panama). We discuss the performance of the network and compare SIM results to those published by the BIPM in its monthly Circular-T document. We also discuss the work that is underway to expand the network.
Proceedings Title
Proc. 2006 Precise Time and
Conference Dates
December 5-7, 2006
Conference Location
Reston, VA


common-view, GPS, international comparisons, time coordination, time scales


Lombardi, M. , Novick, A. , Lopez, J. , Boulanger, J. and Donado, C. (2006), Time Coordination Throughout the Americas via the SIM Common-View GPS Network, Proc. 2006 Precise Time and, Reston, VA, [online], (Accessed March 5, 2024)
Created December 5, 2006, Updated January 27, 2020