Effect of the stratosphere on star image motion.

The joint effect of non-Kolmogorov stratospheric and Kolmogorov tropospheric turbulence on star image motion is studied, and the theoretical predictions are compared with measured data. It is shown that for a large telescope the stratospheric effect has been dramatically underestimated. The techniques that permitted us to single out the contribution of the stratosphere to star image motion and to exclude the effect of uncontrolled telescope motion on the measured data are described.