Troposphere refraction state classification using measured attenuation of non-line-of-sight microwave links

A new method is introduced to determine the troposphere refraction state from the measured field strength of a non-line-of-sight microwave link. The classification procedure is proposed for diffraction paths with a single knife-edge obstacle and recognizes three states of radiowave propagation in the atmosphere: sub-refraction, super-refraction and standard atmosphere. Comparisons of the classification results based on the measured field strength and meteorological measurements are presented to validate the method.