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Some consequences of atmospheric dispersion for ELTs

Owner-Petersen, Mette LU and Gontcharov, Alexander LU (2004) Ground-Based Telescopes In Proceedings of the SPIE - The International Society for Optical Engineering 5489(1). p.507-517
Abstract
Previously the effect of atmospheric dispersion on telescope performance has attracted only relatively little attention. This may be due to the fact that the dispersion effects have been evaluated in relation to the size of the diffraction limited resolution angle of current telescopes, or to seeing limited telescopes. However, since the resolution angle is inversely proportional to telescope diameter, dispersion and dispersion compensation becomes increasingly important for extremely large telescopes (ELTs). In this paper we present a simple model for the dispersion effects in telescopes with adaptive optics (AO). The model addresses the expected loss in Strehl ratio when the atmospheric wavefront error is measured at a wavelength... (More)
Previously the effect of atmospheric dispersion on telescope performance has attracted only relatively little attention. This may be due to the fact that the dispersion effects have been evaluated in relation to the size of the diffraction limited resolution angle of current telescopes, or to seeing limited telescopes. However, since the resolution angle is inversely proportional to telescope diameter, dispersion and dispersion compensation becomes increasingly important for extremely large telescopes (ELTs). In this paper we present a simple model for the dispersion effects in telescopes with adaptive optics (AO). The model addresses the expected loss in Strehl ratio when the atmospheric wavefront error is measured at a wavelength different from the wavelength of observation. Also, the bandwidth over which the correction will be of a given quality is evaluated. Related to AO performance, the consequence of using laser guide stars (LGSs) for probing the atmosphere may be that the measured wavefront error must be rescaled to the wavelength of observation. This places special demands on the AO control loop. Since linear atmospheric dispersion compensation need not cover a larger bandwidth than the AO compensation, an atmospheric dispersion compensator (ADC) can be designed for narrow band operation. As an example of the benefits to be obtained from this, we briefly present the proposed ADC for the Euro50 (Less)
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author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
atmospheric dispersion compensator, Euro50, dispersion compensation, atmospheric wavefront error, Strehl ratio, telescope diameter, diffraction limited resolution angle, extremely large telescopes, adaptive optics, AO control loop, laser guide stars
in
Proceedings of the SPIE - The International Society for Optical Engineering
volume
5489
issue
1
pages
507 - 517
publisher
SPIE
conference name
Ground-Based Telescopes
external identifiers
  • wos:000224524300050
  • other:CODEN: PSISDG
  • scopus:10344267527
ISSN
0277-786X
1996-756X
DOI
10.1117/12.551371
language
English
LU publication?
yes
id
cd39acad-3909-4d96-91e4-c0d29633796e (old id 614864)
date added to LUP
2007-12-04 12:57:16
date last changed
2017-11-20 15:06:02
@inproceedings{cd39acad-3909-4d96-91e4-c0d29633796e,
  abstract     = {Previously the effect of atmospheric dispersion on telescope performance has attracted only relatively little attention. This may be due to the fact that the dispersion effects have been evaluated in relation to the size of the diffraction limited resolution angle of current telescopes, or to seeing limited telescopes. However, since the resolution angle is inversely proportional to telescope diameter, dispersion and dispersion compensation becomes increasingly important for extremely large telescopes (ELTs). In this paper we present a simple model for the dispersion effects in telescopes with adaptive optics (AO). The model addresses the expected loss in Strehl ratio when the atmospheric wavefront error is measured at a wavelength different from the wavelength of observation. Also, the bandwidth over which the correction will be of a given quality is evaluated. Related to AO performance, the consequence of using laser guide stars (LGSs) for probing the atmosphere may be that the measured wavefront error must be rescaled to the wavelength of observation. This places special demands on the AO control loop. Since linear atmospheric dispersion compensation need not cover a larger bandwidth than the AO compensation, an atmospheric dispersion compensator (ADC) can be designed for narrow band operation. As an example of the benefits to be obtained from this, we briefly present the proposed ADC for the Euro50},
  author       = {Owner-Petersen, Mette and Gontcharov, Alexander},
  booktitle    = {Proceedings of the SPIE - The International Society for Optical Engineering},
  issn         = {0277-786X},
  keyword      = {atmospheric dispersion compensator,Euro50,dispersion compensation,atmospheric wavefront error,Strehl ratio,telescope diameter,diffraction limited resolution angle,extremely large telescopes,adaptive optics,AO control loop,laser guide stars},
  language     = {eng},
  number       = {1},
  pages        = {507--517},
  publisher    = {SPIE},
  title        = {Some consequences of atmospheric dispersion for ELTs},
  url          = {http://dx.doi.org/10.1117/12.551371},
  volume       = {5489},
  year         = {2004},
}