By use of a laser remote-sensing technique, the fluctuation profiles of the refractive index of the troposphere were measured at Chester, N. J. The measurements were made with a ground-based optical tracker that tracks a retroreflector mounted on a tethered balloon. The balloon was flown at several altitudes and the flux scintillation on the returned beam was measured. From the scintillation data obtained, the structure constant, which is a measure of the strength of turbulence, was estimated as a function of altitude. The measurements were made during day time in the winter of 1969 and the summer of 1970. The average refractive-index-fluctuation profiles for the winter and the summer months show the turbulence close to the ground in summer months to be greater than that in winter months, by approximately a factor of 3.
M. SUBRAMANIAN, "Laser Remote Sensing of Atmospheric Refractive-Index-Fluctuation Profile," J. Opt. Soc. Am. 62, 677-681 (1972)