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Proceedings Paper • Open Access

Image-based wavefront correction for space telescopes
Author(s): Orestis Kazasidis; Sven Verpoort; Ulrich Wittrock

Paper Abstract

With a view to future large space telescopes, we investigate image-based wavefront correction with active optics. We use an image-sharpness metric as merit function to evaluate the image quality, and the Zernike modes as control variables. In severely aberrated systems, the Zernike modes are not orthogonal to each other with respect to this merit function. Using wavefront maps, the PSF, and the MTF, we discuss the physical causes for the non-orthogonality of the Zernike modes with respect to the merit function. We show that for combinations of Zernike modes with the same azimuthal order, a flatter wavefront in the central region of the aperture is more important than the RMS wavefront error across the full aperture for achieving a better merit function. The non-orthogonality of the Zernike modes with respect to the merit function should be taken into account when designing the algorithm for image-based wavefront correction, because it may slow down the process or lead to premature convergence.

Paper Details

Date Published: 12 July 2019
PDF: 13 pages
Proc. SPIE 11180, International Conference on Space Optics — ICSO 2018, 111807Z (12 July 2019); doi: 10.1117/12.2536206
Show Author Affiliations
Orestis Kazasidis, Münster Univ. of Applied Sciences (Germany)
Sven Verpoort, Münster Univ. of Applied Sciences (Germany)
Ulrich Wittrock, Münster Univ. of Applied Sciences (Germany)


Published in SPIE Proceedings Vol. 11180:
International Conference on Space Optics — ICSO 2018
Zoran Sodnik; Nikos Karafolas; Bruno Cugny, Editor(s)

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