Measuring transmission and forces from observatory equipment vibration
Abstract
We describe measurements of both the vibration forces imparted by various types of observatory equipment, and the transmission of these forces through the soil, foundations and telescope pier. These are key uncertainties both in understanding how to mitigate vibration at existing observatories and for developing a vibration budget in the design of future observatories such as the Thirty Meter Telescope. Typical vibration surveys have measured only the resulting motion (acceleration); however, this depends on both the source and the system being excited (for example, isolating equipment results in less force being transmitted, but greater motion of the equipment itself). Instead, here we (a) apply a known force input to the pier from a shaker and measure the response at different locations, and (b) use isolator properties combined with measured acceleration to infer the forces applied by various equipment directly. The soil foundation and pier transmission can then be combined with a finite element model based vibration transmission analysis to estimate the optical consequences. Estimates of plausible source levels supports the development of a vibration budget for TMT that allocates allowable forces to the sources of vibration; this is described in a companion paper.
Additional Information
© 2014 SPIE. The TMT Project gratefully acknowledges the support of the TMT collaborating institutions. They are the Association of Canadian Universities for Research in Astronomy (ACURA), the California Institute of Technology, the University of California, the National Astronomical Observatory of Japan, the National Astronomical Observatories of China and their consortium partners, and the Department of Science and Technology of India and their supported institutes. This work was supported as well by the Gordon and Betty Moore Foundation, the Canada Foundation for Innovation, the Ontario Ministry of Research and Innovation, the National Research Council of Canada, the Natural Sciences and Engineering Research Council of Canada, the British Columbia Knowledge Development Fund, the Association of Universities for Research in Astronomy (AURA), the U.S. National Science Foundation and the National Institutes of Natural Sciences of Japan.Attached Files
Published - Thompson_2014p91454G.pdf
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Additional details
- Eprint ID
- 58250
- Resolver ID
- CaltechAUTHORS:20150615-125519720
- Gordon and Betty Moore Foundation
- Canada Foundation for Innovation
- Ontario Ministry of Research and Innovation
- National Research Council of Canada
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- British Columbia Knowledge Development Fund
- Association of Universities for Research in Astronomy (AURA)
- NSF
- National Institutes of Natural Sciences of Japan
- Association of Canadian Universities for Research in Astronomy (ACURA)
- Caltech
- University of California
- National Astronomical Observatory of Japan
- National Astronomical Observatories of China
- Department of Science and Technology of India
- Created
-
2015-06-19Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Series Name
- Proceedings of SPIE
- Series Volume or Issue Number
- 9145