Prolonged Space-Wave Fadeouts at 1,046 MC Observed in Cheyenne Mountain Propagation Program

During the first year of continuous operation of the Cheyenne Mountain propagation program, recordings of 1,046-mc fields at receiving locations within the radio horizon have exhibited "fadeouts" or prolonged periods of attenuation often in excess of 20 db below the monthly median level and lasting from a minute up to several hours. The occurrence of these fadeouts has been found to coincide with widespread super-refraction as evidenced by enhanced signals beyond the radio horizon and ground modification of the refractive index profile.