The largest optical telescopes in the world today are the twin 10m Keck telescopes
on Mauna Kea. These telescopes are enabled by active control. The primary mirror
is composed of 36 segments, using control to maintain an
optically smooth surface. Using a similar approach, design work is now underway on the 30m California Extremely Large Telescope (CELT). The current concept has 1080 segments in the primary mirror, requiring 3240 actuators to control the position of each segment to an accuracy of 10's of nanometers in the presence of gravity and wind disturbances. In addition, adaptive optics will be used to compensate for atmospheric turbulence; this control system may involve as many as 20000 actuators with feedback from wavefront information. The control problems for the Keck and CELT telescopes are discussed, including modeling, actuation, sensing, and feedback control.
Copy of presentation [pdf]
This seminar is being presented as part of CDS 101, Principles of Feedback and Control. If you would like to be added to the mailing list to receive future CDS 101 seminar announcements, you can subscribe to the cds101-announce mailing list.