0

Full Content is available to subscribers

Subscribe/Learn More  >
Proceedings Article

MMT adaptive secondary: first AO closed-loop results

[+] Author Affiliations
Guido Brusa

Steward Observatory/Univ. of Arizona (USA) and Osservatorio Astrofisico di Arcetri (Italy)

Armando Riccardi

Osservatorio Astrofisico di Arcetri/INAF (Italy)

Francois P. Wildi, Michael Lloyd-Hart, Hubert M. Martin, Richard Allen, Donald L. Fisher, Douglas L. Miller

Steward Observatory/Univ. of Arizona (USA)

Roberto Biasi

MicroGate Srl (Italy)

Daniele Gallieni

ADS International Srl (Italy)

Fabio Zocchi

Media Lario Srl (Italy)

Proc. SPIE 5169, Astronomical Adaptive Optics Systems and Applications, 26 (December 31, 2003); doi:10.1117/12.508411
Text Size: A A A
From Conference Volume 5169

  • Astronomical Adaptive Optics Systems and Applications
  • Robert K. Tyson; Michael Lloyd-Hart
  • San Diego, California, USA | August 03, 2003

abstract

The adaptive secondary for the MMT is the first mirror of its kind. It was designed to allow the application of wavefront corrections (including tip-tilt) directly at the secondary mirror location. Among the advantages of such a choice for adaptive optics operation are higher throughput, lower emissivity, and simpler optical setup. Furthermore, this specific implementation provides capabilities that are not found in most correctors including internal position feedback, large stroke (to allow chopping) and provision for absolute position calibration. The mirror has now been used at the MMT during several runs where it has performed reliably. In this paper we discuss the mirror operation and AO performance achieved during these runs in which the adaptive secondary has been operating in conjunction with a Shack-Hartmann wavefront sensor as part of the MMT adaptive optics system. In particular we mention a residual mirror position error due to wind buffeting and other errors of ≈ 15 nm rms surface and a stable closed loop operation with a 0dB point of the error transfer function in the range 20-30 Hz limited mainly by the wavefront sensor maximum frame rate. Because of the location of the adaptive secondary with respect to the wavefront sensor camera, reimaging optics are required in order to perform the optical interaction matrix measurements needed to run the AO loop. This optical setup has been used in the lab but not replicated at the telescope so far. We will discuss the effects of the lack of such an internal calibration on the AO loop performances and a possible alternative to the lab calibration technique that uses directly light from sky objects.

© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Citation

Guido Brusa ; Armando Riccardi ; Francois P. Wildi ; Michael Lloyd-Hart ; Hubert M. Martin, et al.
"MMT adaptive secondary: first AO closed-loop results", Proc. SPIE 5169, Astronomical Adaptive Optics Systems and Applications, 26 (December 31, 2003); doi:10.1117/12.508411; http://dx.doi.org/10.1117/12.508411


Access This Article
Sign In to Access Full Content
Please Wait... Processing your request... Please Wait.
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
 

Figures

Tables

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement


Buy this article ($18 for members, $25 for non-members).
Sign In