Anti-aliasing wave-front reconstruction with Shack-Hartmann sensors
نویسندگان
چکیده
The discrete sampling of a wave-front using a Shack-Hartmann sensor limits the maximum spatial frequency we can measure and impacts sensitivity to frequencies at the high end of the correction band due to aliasing. Here we present Wiener filters for wave-front reconstruction in the spatial-frequency domain, ideally suited for systems with a high number of degrees of freedom. We develop a theoretical anti-aliasing (AA) Wiener filter that optimally takes into account high-order wave-front terms folded in-band during the sensing (i.e., discrete sampling) process. We present Monte-Carlo simulation results for residual wavefronts and propagated noise and compare to standard reconstruction techniques (in the spatial domain). To cope with finite telescope aperture we’ve developed and optimised a Gerchberg-Saxton like iterative-algorithm that provides superior performance.
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