A Ray-Tracing Analysis of a Prolonged Fadeout on an Obstacle-Diffraction Radio Path

A prolonged fadeout on a long obstacle-diffraction radio path was probably caused by persistent super-refractive conditions in the lower atmosphere. Ray tracings based upon the observed refractivity profiles at nearby radiosonde stations indicated that during the outage period the beam intersected several high ridges in front of the diffracting obstacle, greatly increasing transmission loss on the circuit. Angle diversity may produce some operational improvement.