ABSTRACT
Atmospheric turbulence affects imaging systems by virtue of wave propagation through a medium with a nonuniform index of refraction. The practical consequence of atmospheric turbulence is that resolution is generally limited by turbulence rather than by the optical design and optical quality of a telescope. This chapter provides a brief discussion of the history of understanding turbulence effects on imaging systems, and the efforts to overcome the limits imposed by atmospheric turbulence. Atmospheric turbulence arises from heating and cooling of the Earth's surface by the sun. The first work to partially overcome the effects of turbulence relied on post detection computer processing of large numbers of short exposure images. Speckle imaging methods suffer from a poor signal-to-noise ratio (SNR) due to the degree of randomness in the atmospheric turbulence-imposed transfer function, and due to the statistics associated with photoelectric detection of light. An alternative post detection processing method has also been used to obtain high resolution images through turbulence.
