Wavefront control system for the Keck telescope

Brase, James M.; An, Jong R.; Avicola, K.; Beeman, B. V.; Gavel, Donald T.; Hurd, Randall L.; Johnston, B. M.; Jones, Holger E.; Kuklo, Thomas C.; Max, C. E.; Olivier, Scot S.; Waltjen, Kenneth E.; Watson, J.

doi:10.1117/12.321687

Cited by 9 publications

(8 citation statements)

References 2 publications

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“…For an AO application one should consider that context switching is done most of the time on very few processes (2)(3)(4)(5)(6)(7)(8). For the fastest machines context switch times for up to 8 processes are below 10 mus, a number that is certainly acceptable.…”

Section: Memory Latency and Context Switching Benchmarking With Lmbenchmentioning

confidence: 98%

Off-the-shelf real-time computers for next-generation adaptive optics

Hippler

Looze

Gäessler

2004

Advancements in Adaptive Optics

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The performance of adaptive optics systems for existing as well as future giant telescopes heavily depends on the number of active wavefront compensating elements, the spatial, and the temporal sampling of the distorted incoming wavefront. In a phase-A study for an extreme adaptive optics system for the VLT (CHEOPS) as well as for LINC-NIRVANA a fizeau interferometer aboard LBT with a multi-conjugated adaptive optics system, we investigate how today's off-theshelf computers compare in terms of floating point computing power, memory bandwidth, input/output bandwidth and real-time behavior. We address questions like how level three cache can impact the memory bandwidth, what matrixvector multiplication performance is achievable, and what can we learn from standard benchmarks running on different architectures.

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Section: Memory Latency and Context Switching Benchmarking With Lmbenchmentioning

confidence: 98%

Off-the-shelf real-time computers for next-generation adaptive optics

Hippler

Looze

Gäessler

2004

Advancements in Adaptive Optics

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“…[35] Norathyriol and its C-glycosylated analogue mangiferin [36] are xanthone natural products isolated from the skin of mangoes that exhibit abroad range of biological activities. [37] Thes ynthesis of 13 is accomplished by cross-coupling of phloroglucinol 10 with 2a on multigram scale (Scheme 3B). Oxidation of the C5 methyl group to the carboxylic acid provides 12,w hich is subsequently converted into 13 by aF riedel-Crafts acylation.…”

Section: Angewandte Chemiementioning

confidence: 99%

A Catalyst‐Controlled Aerobic Coupling of ortho‐Quinones and Phenols Applied to the Synthesis of Aryl Ethers

Huang

Lumb

2016

Angewandte Chemie

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ortho-Quinones are underutilized six-carbon-atom building blocks.W eh erein describe an approach for controlling their reactivity with copper that gives rise to ac atalytic aerobic cross-coupling with phenols.T he resulting aryl ethers are generated in high yield across ab road substrate scope under mild conditions.T his method represents au nique example where the covalent modification of an ortho-quinone is catalyzedb yatransition metal, creating new opportunities for their utilization in synthesis.Supportinginformation for this article can be found under: http://dx.

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“…The WFC consists of two separate real-time control loops: a tip-tilt coniroller to remove tilt from the incoming wavefront [3], and a deformable mirror controller to remove higher-order aberrations [4]. A block diagram of the two nested control loops is shown in Figure 1.…”

Section: Atmospheric Wavefront Disturbancementioning

confidence: 99%

“…It is discussed in detail in reference [4]. The controller initially receives raw CCD image data from the wavefront sensor (a Hartmann sensor using an Adaptive Optics Associates camera with a MiT Lincoln Lab CCD) and computes centroids for each of the subapertures using a quad-cell calculation to estimate the wavefront gradient.…”

Section: The Deformable Mirror Controllermentioning

confidence: 99%

<title>Initial performance of the Keck AO wavefront controller system</title>

Johansson

Acton

et al. 2000

SPIE Proceedings

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The wavefront controller for the Keck Observatory AO system consists of two separate real-time control loops: a tip-tilt control ioop to remove tilt from the incoming wavefront, and a deformable mirror conirol loop to remove higher-order aberrations. In this paper, we describe these control loops and analyze their performance using diagnostic data acquired during the integration and testing of the AO system on the telescope. Disturbance rejection curves for the controllers are calculated from the experimental data and compared to theory. The residual wavefront errors due to control loop bandwidth are also calculated from the data, and possible improvements to the controller performance are discussed.

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Wavefront control system for the Keck telescope

Cited by 9 publications

References 2 publications

Off-the-shelf real-time computers for next-generation adaptive optics

Off-the-shelf real-time computers for next-generation adaptive optics

A Catalyst‐Controlled Aerobic Coupling of ortho‐Quinones and Phenols Applied to the Synthesis of Aryl Ethers

<title>Initial performance of the Keck AO wavefront controller system</title>

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