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Search Publications by: Michael A. Lombardi (Assoc)

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Displaying 76 - 100 of 287

A new algorithm for clock weights for the SIM time scale

May 24, 2012
Author(s)
Michael A. Lombardi, J. Mauricio Lopez-Romero, Nelida Diaz-Munoz, E. de Carlos-Lopez
A time and frequency comparison system has been developed for the Sistema Interamericano de Metrologia (SIM) region in order to compare in real time the time references maintained at the SIM national metrology institutes (NMIs). Since January 2010 a

Automated Clock Comparisons and Time Scale Generation in the SIM Region

April 21, 2012
Author(s)
Michael A. Lombardi, J. Mauricio Lopez-Romero, Nelida Diaz-Munoz
The second, the base unit of time interval in the International System, is defined in terms of the two hyperfine states of the Cesium atom ground energy level. This definition has so far served the metrology community well, and the uncertainty of the best

The Evolution of Time Measurement Part V: Radio Controlled Clocks

April 1, 2012
Author(s)
Michael A. Lombardi
A historical article about the origins and the development of radio controlled clocks (Part IV of a IV-part series). It describes the first time signal radio stations, the early use of telegraphic time codes, and the modern use of digital time codes. It

The Evolution of Time Measurement, Part 2 - Quartz Clocks

October 1, 2011
Author(s)
Michael A. Lombardi
A historical article about the origins and the development of quartz clocks and oscillators (Part II of a IV-part series). It describes the discovery of piezoelectricity, the development of the first quartz oscillators, how quartz oscillators were

An Interlaboratory Stopwatch Comparison in the SIM Region

September 1, 2011
Author(s)
Michael A. Lombardi, Raul Solis, Harold Sanchez, J. Mauricio Lopez-Romero, Francisco Jimenez, Henry Postigo, Daniel Perez, Walter Adad, Victor Masi, Ahmed Ibrahim, Bill Hoger, Ricardo de Carvalho, Jose L. Kronenberg, Gustavo C. Orozco, Theodore Reddock, Leonardo Trigo
Stopwatches and timers are used for an almost unlimited number of applications and are among the most common devices calibrated by metrology laboratories. In large nations, stopwatch calibrations are typically handled by secondary laboratories, such as

Real-Time Generation of the SIM Time Scale (SIMT) from International Clock Comparisons

August 13, 2011
Author(s)
Michael A. Lombardi, Jose M. Lopez, Andrew N. Novick, Francisco Jimenez, Nelida Diaz-Munoz, Eduardo de Carlos Lopez, Jean-Simon Boulanger, Raymond Pelletier, Ricardo de Carvalho, Raul Solis, Harold Sanchez, Liz C. Forero, Junior Gordon, Daniel Perez, Eduardo Bances, Leonardo Trigo, Victor Masi, Henry Postigo, Anthony Questelles, Anselm Gittens, Rodrigo Ramos P.
The Sistema Interamericano de Metrologia (SIM) is one of the world’s five major regional metrology organizations (RMOs). The SIM members are the national metrology institutes (NMIs) located in the 34 nations of the Organization of American States (OAS)

The SIM Time Network

March 1, 2011
Author(s)
Michael A. Lombardi, Andrew N. Novick, J. Mauricio Lopez-Romero, Francisco Jimenez, Eduardo de Carlos Lopez, Jean-Simon Boulanger, Raymond Pelletier, Ricardo de Carvalho, Raul Solis, Harold Sanchez, Carlos A. Quevedo, Gregory Pascoe, Daniel Perez, Eduardo Bances, Leonardo Trigo, Victor Masil, Henry Postigo, Anthony Questelles
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

SIM time scales

October 27, 2010
Author(s)
Michael A. Lombardi, J. Mauricio Lopez-Romero, Nelida Diaz-Munoz
This paper presents an analysis of the performance of some of the time scales generated in the Sistema Interamericano de Metrologia (SIM) region. We emphasize the generation of the first international time scale in near real time, the SIM Time scale (SIMT)

The Development of a Unified Time and Frequency Program in the SIM Region

September 1, 2010
Author(s)
Michael A. Lombardi, J. Mauricio Lopez-Romero
The Sistema Interamericano de Metrologia (SIM) is one of five major regional metrology organizations (RMOs) recognized by the Bureau International des Poids et Mesures (BIPM). SIM is composed of the national metrology institutes (NMIs) located in the 34