Active compensation of flexure on the High-Resolution Optical Spectrograph for Gemini
Paolo D'Arrigo, Francisco Diego, David D. Walker
Gravity-induced flexure has been a long-standing challenge in Cassegrain spectrographs at 4-meter class telescopes; it is the more so at the scale of 8-meter telescopes. This is of particular concern for the Gemini high resolution optical spectrograph, which will be Cassegrain-mounted for its routine mode of operation. In this paper we address the general flexure problem, and how to solve it with the use of active optics. We also present the results of an experimental active flexure compensation system for the ISIS (intermediate- dispersion spectroscopic and imaging system) spectrograph on the 4.2 m William Herschel Telescope (WHT). This instrument, called ISAAC (ISIS spectrograph automatic active collimator), is based on the concept of active correction, where spectrum drifts, due to the spectrograph flexing under the effect of gravity, are compensated by the movement of an active optical element (in this case a fine steering tip-tilt collimator mirror). The experiment showed that active compensation can reduce flexure down to less than 3 micrometer over four hours of telescope motions, dramatically improving the spectrograph performance. The results of the experiment are used to discuss a flexure compensation system for the high resolution optical spectrograph (HROS) for the 8 m Gemini telescope.
Optical Telescopes of Today and Tomorrow 1996
Arne L. Ardeberg
https://doi.org/10.1117/12.269021
Published - 21 Mar 1997
Optical Telescopes of Today and Tomorrow - Landskrona/Hven, Swed
Proceedings of SPIE - The International Society for Optical Engineering
Optical Telescopes of Today and Tomorrow
Landskrona/Hven, Swed
D'Arrigo, P., Diego, F., & Walker, D. D. (1997). Active compensation of flexure on the High-Resolution Optical Spectrograph for Gemini. In A. L. Ardeberg (Ed.), Optical Telescopes of Today and Tomorrow 1996 (pp. 1306-1317). (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 2871). SPIE. https://doi.org/10.1117/12.269021
D'Arrigo, Paolo ; Diego, Francisco ; Walker, David D. / Active compensation of flexure on the High-Resolution Optical Spectrograph for Gemini. Optical Telescopes of Today and Tomorrow 1996. editor / Arne L. Ardeberg. SPIE, 1997. pp. 1306-1317 (Proceedings of SPIE - The International Society for Optical Engineering).
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title = "Active compensation of flexure on the High-Resolution Optical Spectrograph for Gemini",
abstract = "Gravity-induced flexure has been a long-standing challenge in Cassegrain spectrographs at 4-meter class telescopes; it is the more so at the scale of 8-meter telescopes. This is of particular concern for the Gemini high resolution optical spectrograph, which will be Cassegrain-mounted for its routine mode of operation. In this paper we address the general flexure problem, and how to solve it with the use of active optics. We also present the results of an experimental active flexure compensation system for the ISIS (intermediate- dispersion spectroscopic and imaging system) spectrograph on the 4.2 m William Herschel Telescope (WHT). This instrument, called ISAAC (ISIS spectrograph automatic active collimator), is based on the concept of active correction, where spectrum drifts, due to the spectrograph flexing under the effect of gravity, are compensated by the movement of an active optical element (in this case a fine steering tip-tilt collimator mirror). The experiment showed that active compensation can reduce flexure down to less than 3 micrometer over four hours of telescope motions, dramatically improving the spectrograph performance. The results of the experiment are used to discuss a flexure compensation system for the high resolution optical spectrograph (HROS) for the 8 m Gemini telescope.",
keywords = "Automation, Gravitation, Optical resolving power, Optics, Performance, Telescopes, Cassegrain spectrograph, Gemini 8-m telescope, William Herschel 4.2-m telescope",
author = "Paolo D'Arrigo and Francisco Diego and Walker, {David D.}",
doi = "10.1117/12.269021",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
editor = "Ardeberg, {Arne L.}",
booktitle = "Optical Telescopes of Today and Tomorrow 1996",
D'Arrigo, P, Diego, F & Walker, DD 1997, Active compensation of flexure on the High-Resolution Optical Spectrograph for Gemini. in AL Ardeberg (ed.), Optical Telescopes of Today and Tomorrow 1996. Proceedings of SPIE - The International Society for Optical Engineering, vol. 2871, SPIE, pp. 1306-1317, Optical Telescopes of Today and Tomorrow, Landskrona/Hven, Swed, 29/05/96. https://doi.org/10.1117/12.269021
Active compensation of flexure on the High-Resolution Optical Spectrograph for Gemini. / D'Arrigo, Paolo; Diego, Francisco; Walker, David D.
Optical Telescopes of Today and Tomorrow 1996. ed. / Arne L. Ardeberg. SPIE, 1997. p. 1306-1317 (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 2871).
T1 - Active compensation of flexure on the High-Resolution Optical Spectrograph for Gemini
AU - D'Arrigo, Paolo
AU - Diego, Francisco
AU - Walker, David D.
N2 - Gravity-induced flexure has been a long-standing challenge in Cassegrain spectrographs at 4-meter class telescopes; it is the more so at the scale of 8-meter telescopes. This is of particular concern for the Gemini high resolution optical spectrograph, which will be Cassegrain-mounted for its routine mode of operation. In this paper we address the general flexure problem, and how to solve it with the use of active optics. We also present the results of an experimental active flexure compensation system for the ISIS (intermediate- dispersion spectroscopic and imaging system) spectrograph on the 4.2 m William Herschel Telescope (WHT). This instrument, called ISAAC (ISIS spectrograph automatic active collimator), is based on the concept of active correction, where spectrum drifts, due to the spectrograph flexing under the effect of gravity, are compensated by the movement of an active optical element (in this case a fine steering tip-tilt collimator mirror). The experiment showed that active compensation can reduce flexure down to less than 3 micrometer over four hours of telescope motions, dramatically improving the spectrograph performance. The results of the experiment are used to discuss a flexure compensation system for the high resolution optical spectrograph (HROS) for the 8 m Gemini telescope.
AB - Gravity-induced flexure has been a long-standing challenge in Cassegrain spectrographs at 4-meter class telescopes; it is the more so at the scale of 8-meter telescopes. This is of particular concern for the Gemini high resolution optical spectrograph, which will be Cassegrain-mounted for its routine mode of operation. In this paper we address the general flexure problem, and how to solve it with the use of active optics. We also present the results of an experimental active flexure compensation system for the ISIS (intermediate- dispersion spectroscopic and imaging system) spectrograph on the 4.2 m William Herschel Telescope (WHT). This instrument, called ISAAC (ISIS spectrograph automatic active collimator), is based on the concept of active correction, where spectrum drifts, due to the spectrograph flexing under the effect of gravity, are compensated by the movement of an active optical element (in this case a fine steering tip-tilt collimator mirror). The experiment showed that active compensation can reduce flexure down to less than 3 micrometer over four hours of telescope motions, dramatically improving the spectrograph performance. The results of the experiment are used to discuss a flexure compensation system for the high resolution optical spectrograph (HROS) for the 8 m Gemini telescope.
KW - Automation
KW - Gravitation
KW - Optical resolving power
KW - Optics
KW - Performance
KW - Telescopes
KW - Cassegrain spectrograph
KW - Gemini 8-m telescope
KW - William Herschel 4.2-m telescope
U2 - 10.1117/12.269021
DO - 10.1117/12.269021
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Optical Telescopes of Today and Tomorrow 1996
A2 - Ardeberg, Arne L.
D'Arrigo P, Diego F, Walker DD. Active compensation of flexure on the High-Resolution Optical Spectrograph for Gemini. In Ardeberg AL, editor, Optical Telescopes of Today and Tomorrow 1996. SPIE. 1997. p. 1306-1317. (Proceedings of SPIE - The International Society for Optical Engineering). https://doi.org/10.1117/12.269021
10.1117/12.269021Licence: Unspecified