Understand and correct for the low wind effect on the SPHERE and GRAVITY+ adaptive optics

Nicolas Pourré; Jean Baptiste Le Bouquin; Julien Milli; Jean-François Sauvage; Thierry Fusco; Carlos Correia; Sylvain Oberti

doi:10.1117/12.2629793

29 August 2022 Understand and correct for the low wind effect on the SPHERE and GRAVITY+ adaptive optics

Nicolas Pourré, Jean Baptiste Le Bouquin, Julien Milli, Jean-François Sauvage, Thierry Fusco, Carlos Correia, Sylvain Oberti

Author Affiliations +

Proceedings Volume 12185, Adaptive Optics Systems VIII; 121855C (2022) https://doi.org/10.1117/12.2629793
Event: SPIE Astronomical Telescopes + Instrumentation, 2022, Montréal, Québec, Canada

Conference Poster

Abstract

The low wind effect is responsible for uncorrected aberrations that reduce the contrast of exoplanet observations during the nights where the atmospheric conditions are the best. This effect arises at the aperture of 8 meter telescopes such as the Very Large Telescope (on SPHERE, Adaptive Optics Facility (AOF)), Subaru (on SCExAO) and Gemini South (GPI). It is a thermal effect occurring at the spiders that hold the secondary mirror. We use numerical simulations to understand why the high-order adaptive optics fail to correct for low wind effect. Our simulations show that the adaptive optics might amplify/create most of the undesired residuals. We propose a mitigation strategy based on both Shack-Hartmann measurements and H-band focal plane images. We speculate that, contrary to a common belief, the low wind effect could be a local effect on the pupil that is spread out by the adaptive optics loop.

Conference Presentation

Citation Download Citation

Nicolas Pourré, Jean Baptiste Le Bouquin, Julien Milli, Jean-François Sauvage, Thierry Fusco, Carlos Correia, and Sylvain Oberti "Understand and correct for the low wind effect on the SPHERE and GRAVITY+ adaptive optics", Proc. SPIE 12185, Adaptive Optics Systems VIII, 121855C (29 August 2022); https://doi.org/10.1117/12.2629793

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available