CONFERENCE PROCEEDINGS
Advanced Search
Home > Journals > J. Astron. Telesc. Instrum. Syst. > Volume 4 > Issue 4 > Article
Open Access
19 November 2018 Advanced wavefront reconstruction methods for segmented Extremely Large Telescope pupils using pyramid sensors
Victoria Hutterer, Iuliia Shatokhina, Andreas Obereder, Ronny Ramlau
Author Affiliations +
Journal of Astronomical Telescopes, Instruments, and Systems, Vol. 4, Issue 4, 049005 (November 2018). https://doi.org/10.1117/1.JATIS.4.4.049005
Abstract
The generation of Extremely Large Telescopes (ELTs) with mirror diameters up to 40 m has thick secondary mirror support structures (also known as spider legs), which cause difficulties in the wavefront reconstruction process. These spider legs create areas where the information of the phase is disconnected on the wavefront sensor detector, leading to pupil fragmentation and a loss of data on selected subapertures. The effects on wavefront reconstruction are differential pistons between segmented areas, leading to poor wavefront reconstruction. The resulting errors make the majority of existing control algorithms unfeasible for telescope systems having spider legs incorporated. A solution, named the split approach, is presented, which suggests to separate reconstruction of segment piston modes from the rest of the wavefront. Further, two methods are introduced for the direct reconstruction of the segment pistons. Due to the separate handling of the piston offsets on the segments, the split approach makes any of the existing phase reconstruction algorithms developed for nonsegmented pupils suitable for wavefront control in the presence of telescope spiders. We present end-to-end simulation results showing accurate, stable, and extremely fast wavefront reconstruction for the first light instrument mid-infrared ELT imager and spectograph of the ELT that is currently under construction.
CC BY: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
Citation Download Citation
Victoria Hutterer, Iuliia Shatokhina, Andreas Obereder, and Ronny Ramlau "Advanced wavefront reconstruction methods for segmented Extremely Large Telescope pupils using pyramid sensors," Journal of Astronomical Telescopes, Instruments, and Systems 4(4), 049005 (19 November 2018). https://doi.org/10.1117/1.JATIS.4.4.049005
Received: 2 July 2018; Accepted: 25 October 2018; Published: 19 November 2018
JOURNAL ARTICLE
 18 PAGES
DOWNLOAD PAPER SAVE TO MY LIBRARY
GET CITATION
Lens.org Logo
CITATIONS
Cited by 12 scholarly publications.
Advertisement
Advertisement
KEYWORDS
Sensors
Wavefront reconstruction
Reconstruction algorithms
Wavefronts
Telescopes
Large telescopes
Device simulation
RELATED CONTENT
Subscribe to Digital Library
Receive Erratum Email Alert
Back to Top