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5 April 1989 Straylight Analysis Of An Aperture Shade Off-Set From The SIRTF Optical Axis
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Adoption of an aperture shade whose axis is off-set from the optical axis of the SIRTF telescope has been proposed by P.K. Davis of the NASA Ames Research Center. Moving the high side of the asymmetric (truncated) shade away from the optical axis can equalize the barrel baffle lengths illuminated by the aperture shade and reduce the dimensions of both the barrel baffle and aperture shade. The straylight performance of this revised design is compared to that of the SIRTF baseline design, which uses a co-axial asymmetric aperture shade. Both designs incorporate a back focal distance of 100cm and Davis's specifications for the primary and secondary cone baffles. Adoption of an off-set aperture shade for SIRTF would slightly degrade its performance, but would not violate any of the straylight requirements. The SIRTF goal of natural background limited observations can be met with known blacks, Class 750 mirror contamination and either aperture shade configuration.
© (1989) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ann St.Clair Dinger "Straylight Analysis Of An Aperture Shade Off-Set From The SIRTF Optical Axis", Proc. SPIE 0967, Stray Light and Contamination in Optical Systems, (5 April 1989);

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