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Variations in propagation delay times for line ten (TV) based time transfersVariation in the propagation delay for a 30 km TV (Line Ten) radio link was evaluated for a series of 30 independent measurements. Time marks from TV Channel 5 WTTG in Washington, D.C. were simultaneously measured at the Johns Hopkins University Applied Physics Laboratory and at the United States Naval Observatory against each stations' local cesium standard clocks. Differences in the stations' cesium clocks were determined by portable cesium clock transfers. Thirty independent timing determinations were made. The root mean square deviation in the propagation delay calculated from the timing determinations was 11 ns. The variations seen in the propagation delays are believed to be caused by environmental factors and by errors in the portable clock timing measurements. In correlating the propagation delay variations with local weather conditions, only a moderate dependence on air temperature and absolute humidity was found.
Document ID
19820012634
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Chiu, M. C.
(Johns Hopkins Univ. Silver Spring, MD, United States)
Shaw, B. W.
(Johns Hopkins Univ. Silver Spring, MD, United States)
Date Acquired
August 10, 2013
Publication Date
March 1, 1982
Publication Information
Publication: NASA. Goddard Space Flight Center Proc. of the 13th Ann. Precise Time and Time Interval (PTTI) Appl. and Planning Meeting
Subject Category
Lasers And Masers
Accession Number
82N20508
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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