Adaptive optics provides a real-time compensation for atmospheric turbulence that severely limits the resolution of ground-based observation systems. The correction quality relies on a key component, that is, the wavefront sensor (WFS). When observing extended sources, WFS precision is limited by anisoplanatism effects. Anisoplanatism induces a variation of the turbulent phase and of the collected flux in the field of view. We study the effect of this phase and scintillation anisoplanatism on wavefront analysis. An analytical expression of the error induced is given in the Rytov regime. The formalism is applied to a solar and an endoatmospheric observation. Scintillation effects are generally disregarded, especially in astronomical conditions. We shall prove that this approximation is not valid with extended objects.
© 2006 Optical Society of America
Atmospheric and Oceanic Optics
Original Manuscript: April 22, 2005
Revised Manuscript: July 27, 2005
Manuscript Accepted: August 12, 2005
Vol. 1, Iss. 4 Virtual Journal for Biomedical Optics
Clélia Robert, Jean-Marc Conan, Vincent Michau, Thierry Fusco, and Nicolas Vedrenne, "Scintillation and phase anisoplanatism in Shack-Hartmann wavefront sensing," J. Opt. Soc. Am. A 23, 613-624 (2006)