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

Hitesh Gajjar; John Menzies; Jian Swiegers; Didier Rozière; Alain Courteville; Sebastien Buous; Bruno Luong

doi:10.1117/12.672103

23 June 2006 Results from the capacitive edge sensing system for the active alignment of the SALT primary mirror

Hitesh Gajjar, John Menzies, Jian Swiegers, Didier Rozière, Alain Courteville, Sebastien Buous, Bruno Luong

Proceedings Volume 6267, Ground-based and Airborne Telescopes; 626737 (2006) https://doi.org/10.1117/12.672103
Event: SPIE Astronomical Telescopes + Instrumentation, 2006, Orlando, Florida , United States

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.

Citation Download Citation

Hitesh Gajjar, John Menzies, Jian Swiegers, Didier Rozière, Alain Courteville, Sebastien Buous, and Bruno Luong "Results from the capacitive edge sensing system for the active alignment of the SALT primary mirror", Proc. SPIE 6267, Ground-based and Airborne Telescopes, 626737 (23 June 2006); https://doi.org/10.1117/12.672103

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