Real time wavefront control system for the Large Synoptic Survey Telescope (LSST)
Abstract
The LSST is an integrated, ground based survey system designed to conduct a decade-long time domain survey of the optical sky. It consists of an 8-meter class wide-field telescope, a 3.2 Gpixel camera, and an automated data processing system. In order to realize the scientific potential of the LSST, its optical system has to provide excellent and consistent image quality across the entire 3.5 degree Field of View. The purpose of the Active Optics System (AOS) is to optimize the image quality by controlling the surface figures of the telescope mirrors and maintaining the relative positions of the optical elements. The basic challenge of the wavefront sensor feedback loop for an LSST type 3-mirror telescope is the near degeneracy of the influence function linking optical degrees of freedom to the measured wavefront errors. Our approach to mitigate this problem is modal control, where a limited number of modes (combinations of optical degrees of freedom) are operated at the sampling rate of the wavefront sensing, while the control bandwidth for the barely observable modes is significantly lower. The paper presents a control strategy based on linear approximations to the system, and the verification of this strategy against system requirements by simulations using more complete, non-linear models for LSST optics and the curvature wavefront sensors.
Additional Information
© 2014 Society of Photo-Optical Instrumentation Engineers (SPIE). LSST project activities are supported in part by the National Science Foundation through Cooperative Support Agreement (CSA) Award No. AST-1227061 under Governing Cooperative Agreement 1258333 managed by the Association of Universities for Research in Astronomy (AURA), and the Department of Energy under contract with the SLAC National Accelerator Laboratory. Additional LSST funding comes from private donations, grants to universities, and in-kind support from LSSTC Institutional Members.Attached Files
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Additional details
- Eprint ID
- 87676
- Resolver ID
- CaltechAUTHORS:20180709-165044523
- AST-1227061
- NSF
- AST-1258333
- NSF
- Association of Universities for Research in Astronomy (AURA)
- Department of Energy (DOE)
- LSSTC Institutional Members
- Created
-
2018-07-10Created from EPrint's datestamp field
- Updated
-
2021-11-15Created from EPrint's last_modified field
- Series Name
- Proceedings of SPIE
- Series Volume or Issue Number
- 9150