Aperture masking interferometry (AMI) transforms a conventional telescope into an interferometric array via a pupil plane mask. By enforcing a known and often linear relationship between pupil-plane phase errors and Fourier phases, AMI allows for the calculation of “self-calibrating” Fourier observables. This enables imaging at moderate contrast down to and inside the classical telescope diffraction limit. AMI’s earliest applications resulted in sub-diffraction-limited angular resolution without adaptive optics. Subsequent observations coupled with powerful adaptive optics systems extended AMI’s reach to fainter targets and longer exposure times, opening doors to a wide range of studies of binaries, protoplanetary disks, and evolved massive stars. AMI has recently led to the first use of interferometry in space via the mask aboard the James Webb Space Telescope Near Infrared Imager and Slitless Spectrograph (JWST/NIRISS). I will give an overview of AMI’s technical and scientific progress over the years, beginning with ground-based studies and ending with a performance analysis of space-based AMI with JWST/NIRISS.
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