Remote Measurement of Differential Atmospheric Velocity 660192
A concept for detection of clear air turbulence utilizing the Doppler frequency shift in laser light backscattered from atmospheric aerosol is described. The concept employs detection of beat frequencies in the output current of a photodetector resulting from photo mixing the backscattered light from two laser pulses illuminating separated volumes of air. Analysis of the spectral and coherence properties of scattered light is given which proves that the basic phenomena exists. The realizability of a practical system depends upon sufficient aerosol densities and higher performance lasers to achieve adequate S/N at useful distances.