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Comparison of wavefront sensor models for simulation of adaptive optics

Wu, Zhiwen LU ; Enmark, Anita LU ; Owner-Petersen, Mette LU and Andersen, Torben LU (2009) In Optics Express 17(22). p.20575-20583
Abstract
The new generation of extremely large telescopes will have adaptive optics. Due to the complexity and cost of such systems, it is important to simulate their performance before construction. Most systems planned will have Shack-Hartmann wavefront sensors. Different mathematical models are available for simulation of such wavefront sensors. The choice of wavefront sensor model strongly influences computation time and simulation accuracy. We have studied the influence of three wavefront sensor models on performance calculations for a generic, adaptive optics (AO) system designed for K-band operation of a 42 m telescope. The performance of this AO system has been investigated both for reduced wavelengths and for reduced r(0) in the K band.... (More)
The new generation of extremely large telescopes will have adaptive optics. Due to the complexity and cost of such systems, it is important to simulate their performance before construction. Most systems planned will have Shack-Hartmann wavefront sensors. Different mathematical models are available for simulation of such wavefront sensors. The choice of wavefront sensor model strongly influences computation time and simulation accuracy. We have studied the influence of three wavefront sensor models on performance calculations for a generic, adaptive optics (AO) system designed for K-band operation of a 42 m telescope. The performance of this AO system has been investigated both for reduced wavelengths and for reduced r(0) in the K band. The telescope AO system was designed for K-band operation, that is both the subaperture size and the actuator pitch were matched to a fixed value of r(0) in the K-band. We find that under certain conditions, such as investigating limiting guide star magnitude for large Strehl-ratios, a full model based on Fraunhofer propagation to the subimages is significantly more accurate. It does however require long computation times. The shortcomings of simpler models based on either direct use of average wavefront tilt over the subapertures for actuator control, or use of the average tilt to move a precalculated point spread function in the subimages are most pronounced for studies of system limitations to operating parameter variations. In the long run, efficient parallelization techniques may be developed to overcome the problem. (C) 2009 Optical Society of America (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Optics Express
volume
17
issue
22
pages
20575 - 20583
publisher
OSA
external identifiers
  • wos:000271629200134
  • scopus:70749090857
ISSN
1094-4087
DOI
10.1364/OE.17.020575
language
English
LU publication?
yes
id
4e14fbef-3221-4a50-9017-aabe2b88f7e4 (old id 1518764)
date added to LUP
2009-12-28 13:40:28
date last changed
2017-01-01 06:04:49
@article{4e14fbef-3221-4a50-9017-aabe2b88f7e4,
  abstract     = {The new generation of extremely large telescopes will have adaptive optics. Due to the complexity and cost of such systems, it is important to simulate their performance before construction. Most systems planned will have Shack-Hartmann wavefront sensors. Different mathematical models are available for simulation of such wavefront sensors. The choice of wavefront sensor model strongly influences computation time and simulation accuracy. We have studied the influence of three wavefront sensor models on performance calculations for a generic, adaptive optics (AO) system designed for K-band operation of a 42 m telescope. The performance of this AO system has been investigated both for reduced wavelengths and for reduced r(0) in the K band. The telescope AO system was designed for K-band operation, that is both the subaperture size and the actuator pitch were matched to a fixed value of r(0) in the K-band. We find that under certain conditions, such as investigating limiting guide star magnitude for large Strehl-ratios, a full model based on Fraunhofer propagation to the subimages is significantly more accurate. It does however require long computation times. The shortcomings of simpler models based on either direct use of average wavefront tilt over the subapertures for actuator control, or use of the average tilt to move a precalculated point spread function in the subimages are most pronounced for studies of system limitations to operating parameter variations. In the long run, efficient parallelization techniques may be developed to overcome the problem. (C) 2009 Optical Society of America},
  author       = {Wu, Zhiwen and Enmark, Anita and Owner-Petersen, Mette and Andersen, Torben},
  issn         = {1094-4087},
  language     = {eng},
  number       = {22},
  pages        = {20575--20583},
  publisher    = {OSA},
  series       = {Optics Express},
  title        = {Comparison of wavefront sensor models for simulation of adaptive optics},
  url          = {http://dx.doi.org/10.1364/OE.17.020575},
  volume       = {17},
  year         = {2009},
}