Paper
12 March 2020 MTF non-redundant distribution for multi-piston errors detection of segmented telescopes
Author Affiliations +
Abstract
We propose a MTF non-redundant distribution method, with which the multi-piston errors of segmented telescope can be detected simultaneously. A mask with a sparse multi-subaperture configuration is set in the exit pupil of the segmented telescope. One subaperture matches to one segment and samples the wave-front reflected by this segment. Coherent diffraction patterns, produced by each pair of the wave-fronts, are recorded as point spread function (PSF). A Fourier transform is performed for the PSF to obtain the optical transfer function (OTF). Then, relationship between the piston error and the amplitudes of the MTF sidelobes is derived. The piston error can be retrieved accurately by this relationship, and the capture range is the coherent length of the operating light. The key to realize a multi-piston errors simultaneous detection using this relationship is to avoid overlap of the MTF sidelobes which formed by each pair of subwaves. We research and derive the MTF model of a mask with a sparse multi-subaperture configuration. According to Fourier optics principle, the MTF distribution of this model is analyzed, and rules for the MTF sidelobes non-redundant distribution are obtained. Simulations have been done to validate the rules. Taking an 18-segment mirror as an example, a mask with a sparse 18 sub-apertures configuration is designed to realize the MTF sidelobes non-redundant distribution. Thus, just need to set a mask with a sparse multi-subaperture configuration in the conjugate plane of the segmented mirror, the piston errors of the full aperture can be retrieved simultaneously.
© (2020) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Weirui Zhao, Tiantian Liu, Lu Zhang, and Yuejin Zhao "MTF non-redundant distribution for multi-piston errors detection of segmented telescopes", Proc. SPIE 11439, 2019 International Conference on Optical Instruments and Technology: Optoelectronic Measurement Technology and Systems, 114391T (12 March 2020); https://doi.org/10.1117/12.2556326
Lens.org Logo
CITATIONS
Cited by 1 scholarly publication.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Modulation transfer functions

Telescopes

Mirrors

James Webb Space Telescope

Point spread functions

Segmented mirrors

Diffraction

Back to Top