Exoplanets & Exomoons

Segment-level Thermal Sensitivity Analysis For Exo-Earth Imaging

By Keith Cowing
Press Release
September 14, 2022
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Segment-level Thermal Sensitivity Analysis For Exo-Earth Imaging
Segment-level wavefront tolerance maps required to maintain a mean dark hole contrast of 10−11 for the narrow-angle APLC at a wavelength of 500 nm. Each segment shows the limit of its surface deformation it can withstand while maintaining the desired contrast. Outer-ring segments are covered more by the APLC apodizer than segments on the inner rings, therefore they have looser tolerance requirements.

We present a segment-level wavefront stability error budget for space telescopes essential for exoplanet detection. We use a detailed finite element model to relate the temperature gradient at the location of the primary mirror to wavefront variations on each of the segment.

We apply the PASTIS sensitivity model forward approach to allocate static tolerances in physical units for each segment, and transfer these tolerances to the temporal domain via a model of the WFS&C architecture in combination with a Zernike phase sensor and science camera.

We finally estimate the close-loop variance and limiting contrast for the segments’ thermo-mechanical modes.

Ananya Sahoo, Iva Laginja, Laurent Pueyo, Remi Soummer, Laura E. Coyle, J. Scott Knight, Matthew East

Comments: 13 pages, 7 figures, appeared in the Proceedings of SPIE Astronomical Telescopes + Instrumentation, 2022
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2209.06762 [astro-ph.IM] (or arXiv:2209.06762v1 [astro-ph.IM] for this version)
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Submission history
From: Ananya Sahoo [view email]
[v1] Wed, 14 Sep 2022 16:32:56 UTC (9,992 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻