The James Webb Space Telescope Aperture Masking Interferometer

Abstract: In less than a year, the James Webb Space Telescope (JWST) will inherit the mantle of being the world's pre-eminent infrared observatory. JWST will carry with it an Aperture Masking Interferometer (AMI) as one of the supported operational modes of the Near-InfraRed Imager and Slitless Spectrograph (NIRISS) instrument. Aboard such a powerful platform, the AMI mode will deliver the most advanced and scientifically capable interferometer ever launched into space, exceeding anything that has gone before it by orders of magnitude in sensitivity. Here we present key aspects of the design and commissioning of this facility: data simulations ($\texttt{ami_sim}$), the extraction of interferometeric observables using two different approaches ($\texttt{IMPLANEIA}$ and $\texttt{AMICAL}$), an updated view of AMI's expected performance, and our reference star vetting programs.