1. Wavefront tolerances of space-based segmented telescopes at very high contrast: Experimental validation
- Author
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Scott D. Will, Laurent Pueyo, Iva Laginja, Laurent M. Mugnier, James Noss, Peter Petrone, Rémi Soummer, Emiel H. Por, Jean-François Sauvage, Keira Brooks, Marshall D. Perrin, DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Space Telescope Science Institute (STSci), University of Rochester [USA], Hexagon Federal, This work was supported by the Action Spécifique Haute Résolution Angulaire (ASHRA) of CNRS/INSU co-funded by CNES. This work was also supported in part by the National Aeronautics and Space Administration under Grant 80NSSC19K0120 issued through the Strategic Astrophysics Technology/Technology Demonstration for Exoplanet Missions Program (SAT-TDEM, PI: R. Soummer). E. H. P is supported by the NASA Hubble Fellowship grant #HST-HF2-51467.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555., and ANR-18-CE31-0018,WOLF,Analyseurs de surface d'onde à filtrage de Fourier pour les optiques adaptatives des télescopes géants(2018)
- Subjects
planets and satellites: detection ,Segmented mirror ,Aperture ,FOS: Physical sciences ,Context (language use) ,Astrophysics ,law.invention ,Telescope ,Optics ,law ,instrumentation: high angular resolution ,Adaptive optics ,Coronagraph ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Physics ,Wavefront ,methods: statistical ,business.industry ,Astrophysics::Instrumentation and Methods for Astrophysics ,techniques: high angular resolution ,Astronomy and Astrophysics ,telescopes ,Cophasing ,Space and Planetary Science ,business ,Astrophysics - Instrumentation and Methods for Astrophysics ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
Context: The detection and characterization of Earth-like exoplanets (exoEarths) from space requires exquisite wavefront stability at contrast levels of $10^{-10}$. On segmented telescopes in particular, aberrations induced by cophasing errors lead to a light leakage through the coronagraph, deteriorating the imaging performance. These need to be limited in order to facilitate the direct imaging of exoEarths. Aims: We perform a laboratory validation of an analytical tolerancing model that allows us to determine wavefront error requirements in the $10^{-6} - 10^{-8}$ contrast regime, for a segmented pupil with a classical Lyot coronagraph. We intend to compare the results to simulations, and we aim to establish an error budget for the segmented mirror on the High-contrast imager for Complex Aperture Telescopes (HiCAT) testbed. Methods: We use the Pair-based Analytical model for Segmented Telescope Imaging from Space (PASTIS) to measure a contrast influence matrix of a real high contrast instrument, and use an analytical model inversion to calculate per-segment wavefront error tolerances. We validate these tolerances on the HiCAT testbed by measuring the contrast response of segmented mirror states that follow these requirements. Results: The experimentally measured optical influence matrix is successfully measured on the HiCAT testbed, and we derive individual segment tolerances from it that correctly yield the targeted contrast levels. Further, the analytical expressions that predict a contrast mean and variance from a given segment covariance matrix are confirmed experimentally., Comment: 16 pages, 16 figures, accepted for publication in A&A
- Published
- 2022