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Search Publications by: Judah Levine (Fed)

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Displaying 76 - 100 of 224

Realizing UTC (NIST) at a Remote Location

December 5, 2008
Author(s)
Judah Levine
I will describe the backup time scale system that I have constructed at the site of the NIST radio stations near Fort Collins, Colorado, and I will compare its performance to the primary ensemble in Boulder. The Fort Collins system is designed to be a

Steering a Time Scale

December 1, 2008
Author(s)
Judah Levine
A time scale is a procedure for combining the data from an ensemble of clocks or frequency standards. The input data to the ensemble algorithm are generally the time (or frequency) differences between each of the members and the reference device for the

A Straightforward Frequency-Estimation Technique for GPS Carrier-Phase Time Transfer

September 15, 2006
Author(s)
C Hackman, Judah Levine, Thomas E. Parker, Dirk Piester, Juergen Becker
GPS carrier-phase time transfer (GPSCPTT) offers high frequency stability at short averaging times, approaching a fractional frequency stability of 10 -15 at an averaging time of 1 d. However, a discontinuity occurs in the time-transfer estimates between

Adding Water Vapor Radiometer Data to GPS Carrier-Phase Time Transfer

December 7, 2004
Author(s)
C Hackman, Judah Levine
When analyzing GPS carrier-phase time transfer (GPSCPTT) data, it is often necessary to estimate the zenith troposphere delay (ZTD) at each site as a function of time. That is because the index of refraction of the troposphere varies rapidly. Both the ZTD

Coping with Overload on the Network Time Protocol Public Servers

December 7, 2004
Author(s)
David Mills, Judah Levine, Richard Schmidt, David Plonka
The public time servers operated by USNO and NIST provide time synchronization, directly or indirectly, to millions of Internet computers today. The load in the form of processor cycles and network traffic has doubled in the last two years and could

A New Technique for Estimating Frequency from GPS Carrier-Phase Time Transfer Data

August 28, 2004
Author(s)
C Hackman, Judah Levine, Tom Parker, Dirk Piester, Juergen Becker
GPS carrier-phase time transfer (GPSCP1T) offers high frequency stability at short averaging times, approaching a fractional frequency stability of 10-15 at averaging times of one day. However, a discontinuity occurs in the time transfer estimates between