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Proceedings Paper

Results from the capacitive edge sensing system for the active alignment of the SALT primary mirror
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Paper Abstract

The 10-m class Southern African Large Telescope (SALT) at Sutherland, South Africa, was inaugurated in November 2005, following completion of all its major sub-systems. It is the largest single optical telescope in the southern hemisphere. The SAMS (Segment Alignment Measurement System) is a unique capacitive edge sensing solution for the active alignment of the SALT primary mirror. Twelve thin film edge sensors are bonded directly onto the edges of each of the 91 segments, with heat-generating control electronics housed remotely in temperature-controlled enclosures. The SAMS is capable of measuring the tip/tilt and piston of each segment, as well as the change in global radius of curvature, a mode normally undetected by such a system. The primary objective was to build a system that offered an excellent cost-to-performance ratio without sacrificing measurement accuracy, a very necessary requirement because of the scale and number of sensors required for large segmented mirrors. This paper describes the results obtained during the commissioning and calibration of the completed system.

Paper Details

Date Published: 23 June 2006
PDF: 9 pages
Proc. SPIE 6267, Ground-based and Airborne Telescopes, 626737 (23 June 2006); doi: 10.1117/12.672103
Show Author Affiliations
Hitesh Gajjar, Southern African Large Telescope, South African Astronomical Observatory (South Africa)
John Menzies, Southern African Large Telescope, South African Astronomical Observatory (South Africa)
Jian Swiegers, Southern African Large Telescope, South African Astronomical Observatory (South Africa)
Didier Rozière, FOGALE Nanotech (France)
Alain Courteville, FOGALE Nanotech (France)
Sebastien Buous, FOGALE Nanotech (France)
Bruno Luong, FOGALE Nanotech (France)


Published in SPIE Proceedings Vol. 6267:
Ground-based and Airborne Telescopes
Larry M. Stepp, Editor(s)

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