Variations in Propagation Delay Times for Line Ten (TV) Based Time Transfers
Abstract
Variation in the propagation delay for a 30 km TV (Line Ten) radio link has been evaluated for a series of 30 independent measurements. Time marks from TV Channel 5 WTTG in Washington, DC were simultaneously measured at JHUIAPL and at the USNO 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 between May 1980 and August 1981. The RMS 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 Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1981
- Accession Number
- ADA497524
Entities
People
- B. W. Shaw
- M. C. Chiu
Organizations
- Johns Hopkins University