Optical propagation through low-level turbulence

Turbulence effects close to the air-ground interface may be expected to be non-Kolmogorov, even if that model is an adequate description of free-air turbulence effects. Direct measurements of the optical effects of propagation through the boundary layer are therefore required and are being undertaken as part of a program in which various potential applications of adaptive optics are being examined. The measurements are intended to characterize the spatio- temporal characteristics of optical wavefronts after propagation through the air-ground boundary layer. The objective in these measurements is to describe the level of performance that will be required in an adaptive system intended to mitigate the deleterious effects of atmospheric propagation on image formation and on other optical measurements. The principles of measurements and the preliminary results are presented.