Turbulence-induced millimeter-wave scintillation compared with micrometeorological measurements

Scintillations of intensity and phase difference were measured at millimeter wavelengths in a horizontally homogeneous atmospheric surface layer. Simultaneous micrometeorological and optical propagation measurements characterized the clear-air turbulence. Predicted and measured propagation statistics are in good agreement. It is shown that the phase structure function showed a rolloff at large spacings as was expected because the outer scale of the turbulence and log-intensity and phase difference are Gaussian random variables. The mutual coherence function is exp(-D/2) to great accuracy, where D is the sum of phase and log-amplitude structure functions. Estimating heat and humidity fluxes from intensity variances is shown to be valid.>