The error of generalized aliasing associated with the limited sampling of the atmospheric turbulence volume due to the finite number of wavefront sensing directions in wide-field-of-view adaptive optics is formally defined. Following a modal approach, we extend the direct problem formulation of star-oriented multi-conjugate adaptive optics (MCAO) to model and quantify this error analytically. We show that the turbulence estimation with the least-squares reconstructor is subject to strong generalized aliasing, in particular affecting the badly seen modes, whereas with the minimum-mean-square-error reconstructor the estimation is little affected. Finally, we show that the application of modal gain optimization techniques in closed-loop MCAO systems is jeopardized by the generalized aliasing error.
© 2010 Optical Society of America
Original Manuscript: April 9, 2010
Revised Manuscript: August 19, 2010
Manuscript Accepted: August 22, 2010
Published: September 22, 2010
Fernando Quirós-Pacheco, Jean-Marc Conan, and Cyril Petit, "Generalized aliasing and its implications in modal gain optimization for multi-conjugate adaptive optics," J. Opt. Soc. Am. A 27, A182-A200 (2010)