Measurement of the average structural characteristic of the atmospheric refractive index

Measurements of the square of the structure constant of the atmospheric refractive index averaged over a 25-km propagation path are presented. The daily behavior of this parameter C
n
²
for 4 days in July, 1969, are shown. The measured values are in the range from 0.5 to 4×10
^-17
cm
^-2/3
.