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Location of the elevation axis in a large optical telescope

Padin, Stephen (2004) Location of the elevation axis in a large optical telescope. Applied Optics, 43 (5). pp. 1097-1107. ISSN 0003-6935.

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Proposed designs for the next generation of large optical telescopes favor a tripod or quadrupod secondary support, and a primary supported from the back, but it is not yet clear whether the elevation axis should be in front of the primary or behind it. A study is described of the effect of elevation-axis location on key performance parameters (fundamental frequency, blockage, and wind-induced secondary decenter) for a 30-m Cassegrain telescope with a mount configuration that is typical of the new designs. For a fast (e.g., f/1) primary, the best location for the elevation axis is behind the primary. The penalty for moving the elevation axis in front of the primary is roughly a 40% decrease in fundamental frequency and a corresponding reduction in the control bandwidth for pointing and optical alignment.

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Additional Information:© 2004 Optical Society of America Received 8 May 2003; revised manuscript received 20 October 2003; accepted 22 October 2003. The author thanks Doug MacMartin and Larry Stepp for helpful comments. This study was supported by the Caltech Discovery Fund.
Issue or Number:5
Record Number:CaltechAUTHORS:PADao04a
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:5662
Deposited By: Archive Administrator
Deposited On:27 Oct 2006
Last Modified:02 Oct 2019 23:25

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