Atmospheric channel performance measurements at 10 to 100 GHz

A diagnostic probe designed to investigate propagation at millimeter wavelengths was operated on 11.8 and 27.2-km line-of-sight paths near Boulder, CO. Fully coherent carrier wave channels at 11.4, 28.8, and 96.1 GHz provide data to analyze fade mechanisms and evaluate frequency dependent performance characteristics of the link. Data during fog, snow, rain, and clear-air fade events are included with statistical analyses of event occurrence, signal levels, and bit error rates. Time delay distortion and amplitude dispersion on the channel are also examined during fading events by the wide-band digital channel operated as an impulse probe. Rain attenuation, path absorption due to water vapor content, and seasonal variations as a function of frequency are presented and described.