The ESO's ELT construction progress

Tamai, Roberto; Koehler, Bertrand; Cirasuolo, M.; Biancat-Marchet, Fabio; Tuti, Mauro; González-Herrera, J. C.

doi:10.1117/12.2562828

Cited by 12 publications

(10 citation statements)

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“…where σ 2 WFS;λ wfs is the variance of the noise at the WFS level, λ wfs is the WFSensing wavelength, λ im is the imaging wavelength, P rec;i is the coefficient that takes into account the propagation of noise in the phase reconstruction process and T filtering is the coefficient that takes into account the propagation of noise in the temporal filtering process. If we assume that statistically all the WFS SAs have the same noise propagation, then we can write: E Q -T A R G E T ; t e m p : i n t r a l i n k -; e 0 0 5 ; 1…”

Section: Noise Propagationmentioning

confidence: 99%

“…Europe has just launched the construction of the largest ground-based telescope: the Extremely Large Telescope (ELT). 1 In operation by 2027, this 40-m giant will answer fundamental questions from the search for and characterization of planets to the formation and evolution of the first galaxies of the universe. Adaptive optics (AO), by correcting in real-time aberrations introduced by the atmosphere, is essential to reach the ultimate performance of this future facility.…”

Section: Introductionmentioning

confidence: 99%

“…The ELT has therefore been designed as an adaptive telescope, which will provide images with an angular resolution of <10 milliarc second in the near infrared. For this purpose, the ELT is equipped with a deformable mirror in its optical train (the fourth mirror of the telescope, alias ELT M4 2 ), as well as six to eight laser stations, 1 to create artificial sources [laser guide stars (LGS)] for wavefront analysis. Laser stars have been used in AO on 8/10-m telescopes for about 20 years now, and their performance is relatively well mastered.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Key wavefront sensors features for laser-assisted tomographic adaptive optics systems on the Extremely Large Telescope

Fusco

Agapito

Neichel

et al. 2022

J. Astron. Telesc. Instrum. Syst.

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Laser guide star (LGS) wave-front sensing (LGSWFS) is a key element of tomographic adaptive optics system. However, when considering Extremely Large Telescope (ELT) scales, the LGS spot elongation becomes so large that it challenges the standard recipes to design LGSWFS. For classical Shack-Hartmann wave-front sensor (SHWFS), which is the current baseline for all ELT LGS-assisted instruments, a trade-off between the pupil spatial sampling [number of sub-apertures (SAs)], the SA field-of-view (FoV) and the pixel sampling within each SA is required. For ELT scales, this trade-off is also driven by strong technical constraints, especially concerning the available detectors and in particular their number of pixels. For SHWFS, a larger field of view per SA allows mitigating the LGS spot truncation, which represents a severe loss of performance due to measurement biases. For a given number of available detectors pixels, the SA FoV is competing with the proper sampling of the LGS spots, and/or the total number of SAs. We proposed a sensitivity analysis, and we explore how these parameters impacts the final performance. In particular, we introduce the concept of super resolution, which allows one to reduce the pupil sampling per WFS and opens an opportunity to propose potential LGSWFS designs providing the best performance for ELT scales.

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Section: Noise Propagationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Key wavefront sensors features for laser-assisted tomographic adaptive optics systems on the Extremely Large Telescope

Fusco

Agapito

Neichel

et al. 2022

J. Astron. Telesc. Instrum. Syst.

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“…The next generation of ground-based astronomical telescopes and associated instrumentation are currently under development. These so-called extremely large telescopes (ELTs) comprise the European Southern Observatory's (ESO) Extremely Large Telescope (the ELT), 1 the Giant Magellan Telescope, 2 and the Thirty Meter Telescope. 3 These ELTs will have primary mirrors of diameter on the order of 25 to 37 m.…”

Section: Introductionmentioning

confidence: 99%

Flip-flop modulation method used with a pyramid wavefront sensor to correct piston segmentation on ELTs

Engler

Louarn

Vérinaud

et al. 2022

J. Astron. Telesc. Instrum. Syst.

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The next generation of ground-based optical telescopes, such as the European Southern Observatory's Extremely Large Telescope (the ELT), will have large support structures (spiders) for the secondary mirror. These spiders have the effect of segmenting the pupil. Without careful control of the wavefront, segment piston (petal modes) errors can develop. We present a flip-flop modulated/unmodulated method for the pyramid wavefront sensor (PWFS) enabling the PWFS to sense petal piston modes. This flip-flop modulation method uses a single PWFS operating in two states: a modulated state and an unmodulated state. An independent controller is used in each state; the modulated state controls the atmospheric turbulence and the unmodulated state only controls petal piston modes. In simulation, we show the flip-flop method working with the wavefront sensor in both K-and R-bands, providing an improvement of 9.9% and 13%, respectively, over a standard modulated PWFS.

show abstract

“…Europe has just launched the construction of the largest ground-based telescope: the ELT. 1 In operation by 2027, this 40m giant will answer fundamental questions from the search for and characterization of planets to the formation and evolution of the first galaxies of the universe. Adaptive Optics (AO), by correcting in real time aberrations introduced by the atmosphere, is essential to reach the ultimate performance of this future facility.…”

Section: Introductionmentioning

confidence: 99%

Key wavefront sensors features for laser-assisted tomographic adaptive optics systems on the Extremely Large Telescope

Fusco,

Agapito,

Neichel

et al. 2022

Preprint

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Laser Guide Star [LGS] wave-front sensing [LGSWFS] is a key element of tomographic Adaptive Optics system. However, when considering Extremely Large Telescope [ELT] scales, the LGS spot elongation becomes so large that it challenges the standard recipes to design LGSWFS. For classical Shack-Hartmann Wave-Front Sensor [SHWFS], which is the current baseline for all ELT LGS-assisted instruments, a trade-off between the pupil spatial sampling (number of sub-apertures), the sub-aperture field-of-view and the pixel sampling within each sub-aperture is required. For ELT scales, this trade-off is also driven by strong technical constraints, especially concerning the available detectors and in particular their number of pixels. For SHWFS, a larger field of view per sub-aperture allows mitigating the LGS spot truncation, which represents a severe loss of performance due to measurement biases. For a given number of available detectors pixels, the sub-aperture Field of View [FoV] is competing with the proper sampling of the LGS spots, and/or the total number of sub-apertures. In this paper we propose a sensitivity analysis, and we explore how these parameters impacts the final performance. In particular we introduce the concept of super resolution, which allows to reduce the pupil sampling per WFS, and opens an opportunity to propose potential LGSWFS designs providing the best performance for ELT scales.

show abstract

The ESO's ELT construction progress

Cited by 12 publications

References 0 publications

Key wavefront sensors features for laser-assisted tomographic adaptive optics systems on the Extremely Large Telescope

Key wavefront sensors features for laser-assisted tomographic adaptive optics systems on the Extremely Large Telescope

Flip-flop modulation method used with a pyramid wavefront sensor to correct piston segmentation on ELTs

Key wavefront sensors features for laser-assisted tomographic adaptive optics systems on the Extremely Large Telescope

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