Quirós-Pacheco Fernando, Conan Jean-Marc, Petit Cyril
The Blackett Laboratory, Imperial College London, London SW7 2BW, UK.
J Opt Soc Am A Opt Image Sci Vis. 2010 Nov 1;27(11):A182-200. doi: 10.1364/JOSAA.27.00A182.
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.
