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Proceedings Paper

Phasing the segments of the Keck and Thirty Meter Telescopes via the narrowband phasing algorithm: chromatic effects
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Paper Abstract

The narrowband phasing algorithm that was originally developed at Keck has largely been replaced by a broad- band algorithm that, although it is slower and less accurate than the former, has proved to be much more robust. A systematic investigation into the lack of robustness of the narrowband algorithm has shown that it results from systematic errors (of order 20 nm) that are wavelength-dependent. These errors are not well-understood at present, but they do not appear to arise from instrumental effects in the Keck phasing cameras, or from the segment coatings. This leaves high spatial frequency aberrations or scattering within 60 mm of the segment edges as the most likely origin of the effect.

Paper Details

Date Published: 27 July 2016
PDF: 12 pages
Proc. SPIE 9906, Ground-based and Airborne Telescopes VI, 99066F (27 July 2016); doi: 10.1117/12.2230748
Show Author Affiliations
Gary Chanan, Univ. of California, Irvine (United States)
Mitchell Troy, Jet Propulsion Lab. (United States)
Nasrat Raouf, Jet Propulsion Lab. (United States)

Published in SPIE Proceedings Vol. 9906:
Ground-based and Airborne Telescopes VI
Helen J. Hall; Roberto Gilmozzi; Heather K. Marshall, Editor(s)

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