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Proceedings Paper

Integrated Sensing And Control System For A Large, Deployable, Wide-Field Optical System
Author(s): John T. Watson; Dennis C. Ehn
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Paper Abstract

Large lightweight deployable optical systems are highly sensitive to structural changes from material aging and from solar heating. Optical tolerances are a fraction of a wavelength of the radiation the system is designed for and the tolerances remain constant regardless of system size. These large three-mirror infrared systems are to be manufactured at normal temperatures and for use at cryogenic temperatures. Even the most uniform optical material known, fused silica, becomes one of the quality limitations at these temperatures. The quality maintenance problem is compounded when many mirror panels must be assembled to provide a single large mirror area. The support structure must keep individual panels accurately located on one mathematical surface to a small fraction of a wavelength of light. The structural materials that are available to mount the mirrors are an order of magnitude poorer in stability than the fused silica mirror panels, thus large structural warpages with time and with the position of the sun must be accommodated by system actuators between the mirror panels and the support structure. A sensing system is described that measures mirror panel-to-panel mismatch and that determines system wavefront as a function of sensor location in the image field. These data are accepted by a central computer control system that deconvolves the control signals. Examples are given of computer simulation of the sensing and control process, showing the number of iterations required to bring a system into optical adjustment.

Paper Details

Date Published: 15 August 1980
PDF: 7 pages
Proc. SPIE 0228, Active Optical Devices and Applications, (15 August 1980); doi: 10.1117/12.958768
Show Author Affiliations
John T. Watson, Itek Corporation (United States)
Dennis C. Ehn, Itek Corporation (United States)


Published in SPIE Proceedings Vol. 0228:
Active Optical Devices and Applications
William J. Cuneo, Editor(s)

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