Characterizing the vibration environments of the Gemini telescopes

Hayward, T. L.; Rippa, Mathew; Bonnet, Henri; Cavedoni, Charles P.; Galvez, Ramon; Gausachs, Gaston; Cho, M.

doi:10.1117/12.2232140

Cited by 4 publications

(7 citation statements)

References 2 publications

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“…For example, the mechanical vibration that is caused by excitations of on-site instruments usually exhibits narrow-band high-frequency components, the structural responses of large telescopes are within a low frequency band of natural resonances, and the atmospheric turbulences exhibit a (roughly) constant component below a corner frequency and a roll-off at high frequency on a Zernike basis [ 25 ]. In addition, the compensation of tip and tilt are one of the main tasks of AO [ 2 , 23 , 26 ]. Hence, an adequate identification of the disturbance source model is of great interest, which, in turn, allows for the development and implementation of effective control techniques.…”

Section: Ao Systemsmentioning

confidence: 99%

“…Currently, the Large Binocular Telescope (LBT) in Arizona, USA, reaches a combined effective aperture of

m, whilst the Gran Telescopio Canarias (GTC) in the Canary Islands, Spain, reaches an effective aperture of

m. This kind of modern telescopes is used for deep universe exploration as well as sharp high-definition images. However, the attainment of such images is subject to the inherent effects of the atmosphere and the vibrations of different equipment that are part of the telescope, see e.g., [ 2 ].…”

Section: Introductionmentioning

confidence: 99%

“…Adaptive optics (AO) is an optical technique that is used to improve astronomical images by compensating the effect of wavefront distortions caused by atmospheric turbulences and mechanical vibrations [ 3 , 4 ]. AO systems are very sensitive to vibrations acting in the propagation of the light [ 2 , 5 , 6 ]. Mechanical vibrations are typically induced by wind or elements within the instrumentation of the system, such as fans and cooling pumps.…”

Section: Introductionmentioning

confidence: 99%

“…Mechanical vibrations are typically induced by wind or elements within the instrumentation of the system, such as fans and cooling pumps. Hence, the modelling and mitigation of disturbances are a subject of increasing importance in many observatories [ 2 , 7 , 8 , 9 , 10 ]. This mitigation is achieved by deforming a deformable mirror (DM) in order to compensate the optical aberrations that are measured by a wavefront sensor (WFS), which, in turn, implies the need for both an accurate model of the complete AO system and adequate controllers.…”

Section: Introductionmentioning

confidence: 99%

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Disturbance Modelling for Minimum Variance Control in Adaptive Optics Systems Using Wavefront Sensor Sampled-Data

Coronel

Carvajal

Escárate

et al. 2021

Sensors

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Modern large telescopes are built based on the effectiveness of adaptive optics systems in mitigating the detrimental effects of wavefront distortions on astronomical images. In astronomical adaptive optics systems, the main sources of wavefront distortions are atmospheric turbulence and mechanical vibrations that are induced by the wind or the instrumentation systems, such as fans and cooling pumps. The mitigation of wavefront distortions is typically attained via a control law that is based on an adequate and accurate model. In this paper, we develop a modelling technique based on continuous-time damped-oscillators and on the Whittle’s likelihood method to estimate the parameters of disturbance models from wavefront sensor time-domain sampled-data. On the other hand, when the model is not accurate, the performance of the minimum variance controller is affected. We show that our modelling and identification techniques not only allow for more accurate estimates, but also for better minimum variance control performance. We illustrate the benefits of our proposal via numerical simulations.

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Section: Ao Systemsmentioning

confidence: 99%

“…Currently, the Large Binocular Telescope (LBT) in Arizona, USA, reaches a combined effective aperture of

m, whilst the Gran Telescopio Canarias (GTC) in the Canary Islands, Spain, reaches an effective aperture of

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Disturbance Modelling for Minimum Variance Control in Adaptive Optics Systems Using Wavefront Sensor Sampled-Data

Coronel

Carvajal

Escárate

et al. 2021

Sensors

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“…ESO undertook a major program at the very large telescope (VLT) to minimize vibration and to define requirements for instruments 1,2 and identify the best low-vibration cooling options for future instruments. 3 Teams at Gemini also undertook a large program to find vibration sources, 4 finding the biggest contributing sources to image degradation were instrument cryocoolers 5 and cooling fans. Similar programs have been run at Keck 6 and the Large Binocular Telescope.…”

Section: Introductionmentioning

confidence: 99%

Management of equipment vibration for extremely large telescopes

Adams

Fordham

Jakob

et al. 2022

J. Astron. Telesc. Instrum. Syst.

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Management of equipment vibration will be a challenge for the upcoming generation of extremely large telescopes (ELTs) (GMT, TMT, and ESO's ELT) and is being dealt with proactively by all three projects. We document the approaches, techniques, and future efforts by all three ELTs in their attempts to manage vibration in their telescopes. We detail the approaches to developing component requirements, characterizing vibration sources, simulating telescope structural movements, and approaches to mitigating source vibrations. We illustrate the iterative approach taken by the three observatories with several examples of concrete processes, measurements, and other details of use to future observatories.

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