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Proceedings Paper • Open Access

Stray light in Picard telescope
Author(s): Pierre Etcheto; Anne Macaire

Paper Abstract

The PICARD space borne instrument observes the Sun from far UV to visible wavelengths. Very high geometrical and radiometric accuracy is required to measure the Sun's local diameter. Thus this instrument is very sensitive to stray light. Multiple reflections between the detector, the mirrors and the filters have been modelled with ASAP 6. They are not very critical for a point source, but for a broad source they add a notable contribution, biasing the edge of the Sun image. Near specular scatter from optics also enlarges the instrumental response, especially at short wavelengths. Scatter from baffles and structures is less critical, but the later need a careful design. To fulfil the mission, stay light shall be predicted very accurately, based on measured data, then taken into account in the image processing. Accuracy depends on the model sampling, the reflectivity and contamination of optics, and the misalignments of the filter wheels.

Paper Details

Date Published: 21 November 2017
PDF: 17 pages
Proc. SPIE 10569, International Conference on Space Optics — ICSO 2000, 105691N (21 November 2017); doi: 10.1117/12.2307923
Show Author Affiliations
Pierre Etcheto, Ctr. National d'Études Spatiales (France)
Anne Macaire, Ctr. National d'Études Spatiales (France)

Published in SPIE Proceedings Vol. 10569:
International Conference on Space Optics — ICSO 2000
Georges Otrio, Editor(s)

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