A 215-Mile 2720-MC radio link

The results from the operation of a 215-mile, 2720- mc radio link are discussed. The link was operated for a period of twenty months. The yearly median signal level was 79 db below free space with a seasonal variation between 12 and 14 db in the hourly medians. If attention is confined to a single season the hourly medians have a log-normal distribution. No diurnal variation was observed. Probability distributions of signal amplitude based on 30- second samples were most commonly Rayleigh although some significant departures from this law did occur. A study of the time variation of the 30-second median shows the standard deviation of these medians five minutes apart to be about 1 db, and thirty minutes apart to be 2.6 db. The same type of analysis is also performed on the hourly medians. A diurnal variation is observed in the fading, with the midafternoon rate being almost twice that recorded during the early morning. Pulse distortion and meteorological correlations are discussed qualitatively.