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Proceedings Paper

The aggregate behavior of branch points: the use of branch point pairing to generate a hidden phase for closed-loop AO
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Paper Abstract

Recent research has shown that branch points, as they appear in astronomical applications, have a rich collective behavior, showing, in particular, that branch point pairs have a well-defined, non-stoichastic velocity, and that once a branch point pairs location is measured, it can be tracked in open-loop adaptive optics operation. The research presented here uses this new information as a priori knowledge in closed-loop AO. Specifically, an algorithm was developed that measures branch point location and velocity at time tk and then uses this to estimate the phase contribution at time tk+n, giving it an effective memory of where branch points appear and allowing it to determine more accurately between real branch points and noise. The output of the new algorithm is used as a second input to the DM control law. Results of initial closed-loop AO tests will be presented.

Paper Details

Date Published: 12 August 2009
PDF: 11 pages
Proc. SPIE 7466, Advanced Wavefront Control: Methods, Devices, and Applications VII, 746607 (12 August 2009); doi: 10.1117/12.827778
Show Author Affiliations
Carolyn M. Tewksbury-Christle, Air Force Research Lab. (United States)
Denis W. Oesch, Air Force Research Lab. (United States)
Darryl J. Sanchez, Air Force Research Lab. (United States)
Patrick R. Kelly, Air Force Research Lab. (United States)


Published in SPIE Proceedings Vol. 7466:
Advanced Wavefront Control: Methods, Devices, and Applications VII
Richard A. Carreras; Troy A. Rhoadarmer; David C. Dayton, Editor(s)

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