Electromagnetic propagation in anisotropic media: Assessment of principal planes angle in a terrestrial link at 18 GHz during intense rainfall

Simultaneous measurements of attenuation and depolarization at 18 GHz collected during a propagation experiment on a 9.5 km terrestrial link were employed to extract information about the angle formed by the principal planes with respect to the canting angle. Tilted polarization planes were adopted in order to increase the system sensitivity and to detect the sign of the angle. The measured canting angle was statistically analyzed and cumulative distributions conditioned to the rain intensity were obtained. In all cases the measured values are found to be confined within a few degrees. The distributions obtained exhibit a significant bias at the lowest rain intensity and a standard deviation ranging from 4 degs, for low rain intensity to 1 deg for high rain intensity.