Results of propagation test at 505 Mc and 4090 Mc on beyond horizon paths

This paper summarizes the results of some radio propagation tests that were conducted for a full year in Newfoundland starting in late 1953. A more detailed paper on these results was declassified in time to be included in the October 1955 issue of the Proceedings of the IRE. The Newfoundland tests were sponsored by the US Air Force to obtain information for engineering beyond horizon radio relay systems. The field work and most of the data analysis was done by the Bell Telephone Company of Canada. From these results and other data it is possible to generalize on the median gain that can be realized beyond the horizon. Theoretically, the variations in antenna gain should be separated from the fading in the transmission path. However, the practical importance of such separation depends largely on whether the realized antenna gain is consistently low when the signal level is low. A correlation of this type was looked for at the time of these tests but no significant correlation was found. Additional tests are needed on antennas that are significantly larger than 100 wavelengths in diameter.