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Fourier-Analysis In Deformable Mirror Settings / submitted by Alexander Blumenschein BSc
AutorInnenBlumenschein, Alexander
Beurteiler / BeurteilerinRamlau, Ronny
ErschienenLinz, 2018
Umfangvii, 102 Seiten : Illustrationen
HochschulschriftUniversität Linz, Masterarbeit, 2018
Schlagwörter (DE)adaptive Optik / Fourier-Analyse
Schlagwörter (EN)adaptive optics / Fourier-analysis
URNurn:nbn:at:at-ubl:1-25471 Persistent Identifier (URN)
 Das Werk ist gemäß den "Hinweisen für BenützerInnen" verfügbar
Fourier-Analysis In Deformable Mirror Settings [1.91 mb]
Zusammenfassung (Englisch)

In the upcoming generation of extremely large telescopes turbulences in the atmosphere or clouds of dust in space can prove to be obstacles to obtaining good quality images. Adaptive Optics (AO) are a modern appraoch to compensate for these disturbances. A Deformable Mirror (DM) is utilised to correct for the appearing disturbances. By adjusting the length of the attached actuators the DM can alter its shape according to the data obtained by a wavefront sensor (WFS). Since we can only employ a finite number of actuators, the approximation of the incoming wavefront is also limited. Together with the layout of the actuators, the influence functions of the repsective actuators may be unable to represent the entire spectrum of frequencies. We can model a mirror shape as a function and the resulting influence functions as the function values at the respective points. By approximating this function via a nodal basis this question translates to the queastion, if there are frequencies, that cannot be displayed in the subspace spanned by the basis functions. We apply the Fourier transform to the basis representation of a function to tarnslate to the frequency domain. The goal of this thesis is to find frequencies that produce zero in the Fourier transform without depending on the specific mirror shape. We do this for the 1D as well as the 2D case.

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