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Search Publications by: Michael A. Lombardi (Assoc)

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Displaying 101 - 125 of 287

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

A NIST Disciplined Oscillator

July 26, 2010
Author(s)
Michael A. Lombardi
The National Institute of Standards and Technology (NIST) now offers a service that provides customers with an oscillator locked to UTC(NIST), the United States national standard for frequency and time. A NIST disciplined oscillator (NISTDO) works by

Challenges in SIM to Create a Coordination Program for Time and Frequency

July 26, 2010
Author(s)
J. Mauricio Lopez-Romero, Michael A. Lombardi
The Sistema Interamericano de Metrologia (SIM), one of the world s five major regional metrology organizations (RMOs) recognized by the Bureau International des Poids et Mesures (BIPM), is comprised of national metrology institutes (NMIs) located in all 34

A common-view disciplined oscillator

May 24, 2010
Author(s)
Michael A. Lombardi, Aaron P. Dahlen
This paper describes a common-view disciplined oscillator (CVDO) that locks to a reference time scale through the use of common-view Global Positioning System (GPS) satellite measurements. A Proportional-Integral-Derivative (PID) controller obtains near

How Accurate is a Radio Controlled Clock?

March 1, 2010
Author(s)
Michael A. Lombardi
This paper discusses the factors that determine the accuracy of radio controlled clocks. The topics covered including the accuracy of the time signal station, path delay, synchronization errors, and the time error that accumulates between synchronizations.

Distributing UTC(NIST) to Industrial Time and Frequency Users

November 18, 2009
Author(s)
Michael A. Lombardi, Victor S. Zhang
The National Institute of Standards and Technology (NIST) maintains one of the world s most accurate and stable time scales, UTC(NIST), as well as the NIST-F1 cesium fountain, the primary frequency standard for the United States. These standards are

WWVB Radio Controlled Clocks: Recommended Practices for Manufacturers and Consumers (2009 edition)

September 8, 2009
Author(s)
Michael A. Lombardi, Andrew N. Novick, John P. Lowe, Matthew J. Deutch, Glenn K. Nelson, Douglas D. Sutton, William C. Yates, D. W. Hanson
Radio controlled clocks represent a true revolution in timekeeping. Clocks that synchronize to NIST radio station WWVB now number in the millions in the United States, and new sales records are being established every year. As a result, many of us are now

Time and Frequency Users Manual

September 2, 2009
Author(s)
Michael A. Lombardi
This book is for the person who needs information about making time and frequency measurements. It is written at a level that will satisfy those with a casual interest as well as laboratory engineers and technicians who use time and frequency every day. It

Establishment of the SIM Time Scale

August 1, 2009
Author(s)
J. Mauricio Lopez-Romero, N. Munoz, Michael A. Lombardi
The SIM time and frequency metrology working group has developed a comparison network for the Americas, with the goals of improving metrology in the SIM region and to allow as many countries as possible to participate in the network. As of May 2008, ten

The SIM Time Network and its Contributions to Metrology in the Americas

April 1, 2009
Author(s)
Michael A. Lombardi
The SIM Time Network (SIMTN) has been one of the great success stories of the Sistema Interamericano de Metrologia (SIM), a regional metrology organization (RMO) that includes the 34 member nations of the Organization of American States (OAS). The SIMTN

Stopwatch and Timer Calibrations (2009 edition)

January 28, 2009
Author(s)
Jeff C. Gust, Robert M. Graham, Michael A. Lombardi
Stopwatch and timer calibrations are perhaps the most common calibrations performed in the field of time and frequency metrology. Hundreds of United States laboratories calibrate many thousands of timing devices annually to meet legal and organizational

PTTI Capabilities of the Modernized LORAN System

December 1, 2008
Author(s)
Kirk Montgomery, Michael A. Lombardi
This paper covers the current status and future plans of the modernized LORAN systems in North America, the European Union, Asia, & Saudi Arabia. Special focus is placed on the enhanced LORAN system in North America and Europe. These modernized systems