Differentiable modelling and data analysis for the JWST Aperture Masking Interferometer

Louis Desdoigts; Benjamin Pope; Peter Tuthill

doi:10.1117/12.3020303

28 August 2024 Differentiable modelling and data analysis for the JWST Aperture Masking Interferometer

Louis Desdoigts, Benjamin Pope, Peter Tuthill

Proceedings Volume 13095, Optical and Infrared Interferometry and Imaging IX; 1309513 (2024) https://doi.org/10.1117/12.3020303
Event: SPIE Astronomical Telescopes + Instrumentation, 2024, Yokohama, Japan

Abstract

The Aperture Masking Interferometer (AMI) on board the James Webb Space Telescope (JWST) has a unique place in observational astronomy as the first imaging interferometer in space, promising highly-precise observations resistant to optical aberrations. While the optical system and Point-Spread Function (PSF) are very stable, the infrared detectors on board suffer from a series of non-linearities – primarily charge migration or the “brighter-fatter effect” that, while challenging for other observing modes, are ruinous to the visibility calibration of the AMI mode. Local nonlinear effects produced cannot be straightforwardly corrected in the Fourier domain. Efforts using the existing pipelines have delivered some improvements, but outcomes remain far from the theoretical photon-noise limit of the instrument. This manuscript presents initial work using a fundamentally different approach: the joint implementation of a differentiable physics model of the optics, and a machine-learned Effective Detector Model (EDM), using dLux. These are trained together end-to-end, by gradient descent using the full ensemble of point-source reference targets so far observed by AMI. We infer highly-precise metrology of the AMI and NIRISS optical systems, a preliminary EDM which restores commissioning data to near-ideal precision, and illustrate initial and final residual noise floors representing the present state of this ongoing project.

Conference Presentation

Citation Download Citation

Louis Desdoigts, Benjamin Pope, and Peter Tuthill "Differentiable modelling and data analysis for the JWST Aperture Masking Interferometer", Proc. SPIE 13095, Optical and Infrared Interferometry and Imaging IX, 1309513 (28 August 2024); https://doi.org/10.1117/12.3020303

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