Millimeter wave propagation turough the turbulent atmosphere

An extensive set of millimeter wave propagation measurements was made during 1983 to 1985 by a team of scientists from NOAA´s Wave Propagation Laboratory and Georgia Institute of Technology. Millimeter wave fre quencies from 116 to 230 GHz were propagated over a 1.4 km horizontal path in Flatville, Illinois. Simultaneous, extensive measurements of the meteorology allowed a detailed comparison of the propagation characteristics with the current state of the atmosphere. We report on the observations of millimeter wave propagation characteristics in clear air. Amplitude and phase spectra for propagation in clear air are compared with theory derived using the weak refractive turbulence approximation. Excellent agreement is found when refraction fluctuations dominate over absorption fluctuations. Further, probability density functions appear to be, respectively, lognormal (amplitude) and Gaussian (phase difference).