&lt;title&gt;Gemini primary mirror cell design&lt;/title&gt;

Huang, Eugene W.

doi:10.1117/12.269051

Cited by 4 publications

(2 citation statements)

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“…The first type uses fixed positioning points to achieve primary mirror positioning and includes the NTT [7], VLT Survey Telescope (VST) [8], Subaru Telescope [9], and Southern Astrophysical Research Telescope (SOAR) [10]. The second type uses virtual positioning points and includes the Advanced Electro-Optical System 3.6 m telescope (AEOS) [11], Very Large Telescope (VLT) [12], and Gemini Telescope [13]. The third type uses a six-hardpoint positioning mechanism for primary mirror positioning, including the MMT Telescope [14], Large Binocular Telescope (LBT) [15,16], and the unfinished Large Synoptic Survey Telescope (LSST) [17,18].…”

Section: Introductionmentioning

confidence: 99%

Active Support System for the Correction of a 4m SiC Primary Mirror Based on the Bending Mode

Yu,

Wu,

Wang

2023

Applied Sciences

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Active optics is a key technology in ground-based large-aperture telescopes. The active correction of the surface shape of the primary mirror is used to reduce the surface shape error and improve the imaging quality. At present, the structure of the active optics support system is not standardized. Therefore, to ensure the imaging quality of a telescope using a 4m SiC (silicon carbide) primary mirror, this article designed an active support system for the primary mirror and comprehensively evaluated the performance of the system. The system used pneumatic actuators to correct the surface shape of the primary mirror and a six-hardpoint positioning mechanism to correct the pose of the primary mirror. A method for compensating for the force on the hardpoints that causes protrusions and dents on the primary mirror surface was proposed, which effectively improved the accuracy of the primary mirror surface. The bending-mode method was used to determine the correction force. To achieve better results in the surface shape correction based on the bending mode, the relationship between the order of the bending modes used in the correction and the correction effect was studied, enabling the system to achieve a higher surface shape accuracy with a smaller correction force. Finally, the performance of the system was evaluated under various conditions, such as under gravity, thermal load, and wind load. The results indicated that the system had good correction effects on the deformation of the primary mirror under various operating conditions and could meet the requirements of optical design for surface accuracy. In conclusion, this study not only verified the application of active optics technology based on the bending mode in large-aperture SiC mirrors, but also improved on the relevant theoretical research on active optics.

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Section: Introductionmentioning

confidence: 99%

Active Support System for the Correction of a 4m SiC Primary Mirror Based on the Bending Mode

Yu,

Wu,

Wang

2023

Applied Sciences

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“…Two main active axial support schemes are often adopted to these meniscus primary mirrors. One option is that the active supports normal to the back surface of the primary mirror, a case in point is the GEMINI telescope [3,4]. The other axial support scheme is defined as those supports whose resultant force is parallel to the optical axis of the primary mirror, such as SUB-ARU [5]], Telescopio Nazionale Galileo (TNG) [6], SOAR [7], VISTA [8] and ATST [9].…”

Section: Introductionmentioning

confidence: 99%

Performance comparison between two axial active support schemes for 1-m thin meniscus primary mirror

Niu

Wang

et al. 2013

J. Inst.

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Active support scheme may decide the deformation of the optical surface figure of the primary mirror. Two main active axial support schemes are often adopted to the thin meniscus primary mirror, one scheme is that the axial supports normal to the mirror bottom surface, and the other is that the active forces parallel to the optical axis. In order to compare the performance of the two support schemes, 1-m thin meniscus primary mirror is conducted. Finite element analysis (FEA) is employed to analyze the optical surface figures of the primary mirror, and optimizations are carried out by using ANSYS for each support scheme to obtain the locations and active forces. The axial support force sensitivities are calculated for the two support schemes in a case that a single axial support has a force error of 0.5 N. The correction ability of the active support system for both of the support schemes are analyzed when an arbitrary axial support is failure. Several low order Zernike modes are modeled with MATLAB procedure, and active optics corrections are applied to these modes for the two active supports. The extra mirror surface error due to thermal deformation is also corrected with the two support schemes.

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The Surface Brightness of MegaConstellation Satellite Trails on Large Telescopes

Ragazzoni

2020

PASP

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On large telescopes, the trails produced by MegaConstellation satellites will be significantly defocused due to their close proximity. As a result, their apparent surface brightness will be, under a range of conditions, almost constant during their apparent sweep across the focal plane. This paper derives a few simple relationships and evaluate the impact of such trails on operations of large optical ground based facilities.

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<title>Gemini primary mirror cell design</title>

Cited by 4 publications

References 1 publication

Active Support System for the Correction of a 4m SiC Primary Mirror Based on the Bending Mode

Active Support System for the Correction of a 4m SiC Primary Mirror Based on the Bending Mode

Performance comparison between two axial active support schemes for 1-m thin meniscus primary mirror

The Surface Brightness of MegaConstellation Satellite Trails on Large Telescopes

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