| 1. |
- Flicker, Ralf, et al.
(författare)
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Tilt anisoplanatism in laser-guide-star-based multiconjugate adaptive optics. Reconstruction of the long exposure point spread function from control loop data
- 2003
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Ingår i: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 400:3, s. 1199-1207
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Tidskriftsartikel (refereegranskat)abstract
- A method is presented for estimating the long exposure point spreadfunction (PSF) degradation due to tilt anisoplanatism in alaser-guide-star-based multiconjugate adaptive optics systems fromcontrol loop data. The algorithm is tested in numerical Monte Carlosimulations of the separately driven low-order null-mode system, and isshown to be robust and accurate with less than 10 relative error inboth H and K bands down to a natural guide star (NGS) magnitude ofmR=21, for a symmetric asterism with three NGS on a 30 arcsec radius.The H band limiting magnitude of the null-mode system due to NGSsignal-to-noise ratio and servo-lag was estimated previously to mR=19.At this magnitude, the relative errors in the reconstructed PSF andStrehl are here found to be less than 5 and 1, suggesting that the PSFretrieval algorithm will be applicable and reliable for the full rangeof operating conditions of the null-mode system.
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| 2. |
- Snel, Ralph, et al.
(författare)
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Some aspects of science with a 50-m AO telescope
- 2003
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Ingår i: Second Backaskog Workshop on Extremely Large Telescopes (Proceedings of the SPIE). - : SPIE. - 0819452998 ; 5382, s. 57-66
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Konferensbidrag (refereegranskat)abstract
- Among the science challenges of the Extremely Large Telescopes (ELTs),four object types are studied for performance with a 50 m ELT withadaptive optics (AO), Euro50. Emphasis is on planetary systems and verydistant objects. For planetary systems and their evolution, we examinehigh resolution imaging of the nuclei of comets and high-resolutionimaging, photometry and low and intermediate resolution spectroscopy ofKuiper-Belt objects. Imaging of Earth-like planets is discussed. Thevery high contrast imaging necessary for these purposes is discussedtogether with the relevant error sources. Finally, photometry andclassification of supernovae is discussed and examined. The performanceof a 50 m AO ELT is compared to corresponding data obtainable withcurrent VLTs equipped with AO.
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