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Building a better flat-field : an instrumental calibration projector for the Large Synoptic Survey Telescope

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dc.contributor.advisor Christopher Stubbs and Nergis Mavalvala. en_US Vaz, Amali L en_US
dc.contributor.other Massachusetts Institute of Technology. Dept. of Physics. en_US 2011-08-30T14:56:47Z 2011-08-30T14:56:47Z 2011 en_US 2011 en_US
dc.description Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2011. en_US
dc.description This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. en_US
dc.description Cataloged from student submitted PDF version of thesis. en_US
dc.description Includes bibliographical references (p. 125-126). en_US
dc.description.abstract The Large Synoptic Survey Telescope (LSST) is a next-generation ground-based survey telescope whose science objectives demand photometric precision at the 1% level. Recent efforts towards 1% photometry have advocated in-situ instrumental calibration schemes that use a calibrated detector, rather than a celestial source, as the fundamental reference point for all measurements of system throughput. Results have been promising, but report systematic errors due to stray and scattered light from the flat-field screens used. The LSST calibration scheme replaces the traditional Lambertian-scattering flat-field screen with an array of projectors whose light is constrained in angle, thereby minimizing scattered light incident on the detector. This thesis presents the construction and testing of a single prototype projector within the LSST array. In particular, we evaluate the use of Engineered Diffusers to define the angular radiance of incident light, and of either a Fresnel lens or parabolic mirror to collimate that light. We find that flat-top Engineered Diffusers produce light that is constrained in angle, but which shows persistent pixel-to-pixel non-uniformity at the 5-10% level, and colorto- color non-uniformity at the 5-15% level; unless compensated, chromatic non-uniformity renders them unsuitable for our purposes. The additional chromatic aberrations introduced by Fresnel lens collimators render such transmissive collimators infeasible. Nevertheless, we demonstrate the soundness of the flat-field projector concept by constructing an alternative projector prototype, based on an integrating sphere, that satisfies each criterion well within our tolerances. The magnitude of improvement granted by the integrating sphere projector suggests that future work further investigate this approach. en_US
dc.description.statementofresponsibility by Amali L. Vaz. en_US
dc.format.extent 126 p. en_US
dc.language.iso eng en_US
dc.publisher Massachusetts Institute of Technology en_US
dc.rights M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. en_US
dc.rights.uri en_US
dc.subject Physics. en_US
dc.title Building a better flat-field : an instrumental calibration projector for the Large Synoptic Survey Telescope en_US
dc.title.alternative Instrumental calibration projector for the Large Synoptic Survey Telescope en_US
dc.type Thesis en_US S.B. en_US
dc.contributor.department Massachusetts Institute of Technology. Dept. of Physics. en_US
dc.identifier.oclc 746926100 en_US

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