The design of the future Extremely Large Telescopes (ELTs) is currently under way. The presence of two segmented mirrors in the optical train has been considered to be of high risk due to the additional challenge of phasing and aligning a telescope having two segmented mirrors. Nevertheless this double segmentation could be a feature of the E-ELT where the optical train will contain a segmented primary and possibly a segmented M4. In this paper we will present some preliminary studies based on numerical simulations demonstrating that with the pyramid wavefront sensor it is possible to control piston, tip, and tilt errors of two segmented mirrors in the same optical train simultaneously.

Date Published: 17 July 2008
PDF: 8 pages
Proc. SPIE 7012, Ground-based and Airborne Telescopes II, 70123E (17 July 2008); doi: 10.1117/12.790575

Published in SPIE Proceedings Vol. 7012:
Ground-based and Airborne Telescopes II
Larry M. Stepp; Roberto Gilmozzi, Editor(s)