OSA's Digital Library

Applied Optics

Applied Optics

APPLICATIONS-CENTERED RESEARCH IN OPTICS

  • Vol. 37, Iss. 21 — Jul. 20, 1998
  • pp: 4586–4597

Real-time modal control implementation for adaptive optics

Allan Wirth, Joseph Navetta, Douglas Looze, Stefan Hippler, Andreas Glindemann, and Donald Hamilton  »View Author Affiliations


Applied Optics, Vol. 37, Issue 21, pp. 4586-4597 (1998)
http://dx.doi.org/10.1364/AO.37.004586


View Full Text Article

Enhanced HTML    Acrobat PDF (1570 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations

Abstract

The electronics, computing hardware, and computing used to provide real-time modal control for a laser guide-star adaptive optics system are presented. This approach offers advantages in the control of unobserved modes, the elimination of unwanted modes (e.g., tip and tilt), and automatic handling of the case of low-resolution lens arrays. In our two-step modal implementation, the input vector of gradients is first decomposed into a Zernike polynomial mode by a least-squares estimate. The number of modes is assumed to be less than or equal to the number of actuators. The mode coefficients are then available for collection and analysis or for the application of modal weights. Thus the modal weights may be changed quickly without recalculating the full matrix. The control-loop integrators are at this point in the algorithm. To calculate the deformable-mirror drive signals, the mode coefficients are converted to the zonal signals by a matrix multiply. When the number of gradients measured is less than the number of actuators, the integration in the control loop will be done on the lower-resolution grid to avoid growth of unobserved modes. These low-resolution data will then be effectively interpolated to yield the deformable-mirror drive signals.

© 1998 Optical Society of America

OCIS Codes
(010.1080) Atmospheric and oceanic optics : Active or adaptive optics
(010.7350) Atmospheric and oceanic optics : Wave-front sensing
(120.4820) Instrumentation, measurement, and metrology : Optical systems

History
Original Manuscript: October 1, 1997
Revised Manuscript: January 20, 1998
Published: July 20, 1998

Citation
Allan Wirth, Joseph Navetta, Douglas Looze, Stefan Hippler, Andreas Glindemann, and Donald Hamilton, "Real-time modal control implementation for adaptive optics," Appl. Opt. 37, 4586-4597 (1998)
http://www.opticsinfobase.org/ao/abstract.cfm?URI=ao-37-21-4586


Sort:  Author  |  Year  |  Journal  |  Reset  

References

  1. J. Beckers, “Adaptive optics for astronomy: principles, performance, and applications,” Annu. Rev. Astron. Astrophys. 31, 13–62 (1993). [CrossRef]
  2. A. Wirth, F. Landers, B. Trvalik, J. Navetta, T. Bruno, “A laser guide star atmospheric compensation system for the 3.5m Calar Alto telescope,” in Adaptive Optics, Vol. 23 of 1995 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1995), paper MA3-1.
  3. R. J. Noll, “Zernike polynomials and atmospheric turbulence,” J. Opt. Soc. Am. 66, 207–211 (1976). [CrossRef]
  4. J. Y. Wang, D. E. Silva, “Wave-front interpretation with Zernike polynomials,” Appl. Opt. 19, 1510–1518 (1980). [CrossRef] [PubMed]
  5. A. Glindemann, M. J. McCaughran, S. Hippler, C. Wagner, R.-R. Rohloff, “CHARM: a tip/tilt tertiary system for the Calar Alto 3.5m telescope,” presented at the OSA summer topical meeting on Adaptive Optics, Maui, 8–12 July 1996.
  6. J. Huang, D. P. Looze, N. Denis, D. Castanon, A. Wirth, “Modeling and identification of adaptive optics systems,” Int. J. Control (to be published).
  7. G. F. Franklin, J. D. Powell, A. Emami-Naeini, Feedback Control of Dynamic Systems (Addison-Wesley, Reading, Mass., 1988).
  8. G. Rousset, J.-L. Beuzit, N. Hubin, E. Gendron, P.-Y. Madec, C. Boyer, J. P. Gaffard, J.-C. Richard, M. Vittot, P. Gigan, P. J. Lena, “Performance and results of the COME-ON+ adaptive optics system at the ESO 3.6m telescope,” in Adaptive Optics in Astronomy, M. A. Ealey, F. Merkle, eds., Proc. SPIE2201, 1088–1095 (1994). [CrossRef]
  9. J. L. Beuzit, N. Hubin, E. Gendron, L. Demailly, P. Gigan, F. Lacombe, F. Chazallet, D. Rabaud, G. Rousset, “ADONIS: a user-friendly adaptive optics system for the ESO 3.6m telescope,” in Adaptive Optics, Vol. 23 of 1995 OSA Technical Digest Series (Optical Society of America, Washington, D.C., 1995), paper MC1-1.
  10. VxWorks is a product of Wind River Systems, Inc., 1010 Atlantic Avenue, Alameda, Calif. 94501.
  11. EPICS is free to nonprofit and government sites from Los Alamos National Laboratories and is commercially available from Kinetic Systems Corp., 7308 South Alton Way, Bldg. 2, Engelwood, Colo. 80112.
  12. Both Tcl and Tk are freely available in the public domain. For further information on these languages, see B. B. Welsh, Practical Programming in Tcl and Tk (Prentice-Hall, Upper Saddle River, N.J., 1995).

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.


« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited