Propagation measurements at 3.6 and 11Gc/s over a line-of-sight radio path

The results of signal-level recordings at 3.6Gc/s and 11Gc/s made simultaneously for a 12-month period over a 55km line-of-sight radio path are given. Two types of fading were encountered: that due to interference between two or more rays and that due to absorption caused by atmospheric precipitation. An attempt is made to correlate the latter with precipitation rate. A method of measuring the changes in elevation angle of received rays at 11Gc/s is described, the results given, and possible effects on gain degradation of narrow-beam aerials are assessed.