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A New Method for Aperture Masking Interferometric Imaging: Demonstration with the JWST

Instrumentation and Methods for Astrophysics 2026-02-25 v1 Accelerator Physics Optics

Abstract

We present a new method for aperture masking interferometric (AMI) imaging at near-IR wavelengths using radio astronomical techniques. The method starts with derivation of interferometric visibilities from a Fourier transform of the interferograms. An iterative joint optimization process is then employed, using self-calibration of the interferometric element-based complex voltage gains (i.e. electric fields), and CLEAN deconvolution to obtain the source structure. We demonstrate the efficacy of the method using the NIRISS aperture masking interferometer on the James Webb Space Telescope (JWST) at 4.8~μ\mum and 3.8~μ\mum. Due to a number of effects (the large pixel size, charge migration, near-field optics), the method also requires an initial visibility-based amplitude normalization using observations of a well know point-source calibration star. We employ early science observations of the dusty binary Wolf-Rayet star WR137. Images with a dynamic range (peak/rms) of 240\sim 240 on the target, and 1000\sim 1000 on the calibrator, are synthesized from a short integration. The self-calibration process determines the photon path-lengths through the optical system to each aperture using data on the target source itself, thereby representing an essentially 'real-time', precise wavefront error sensor. Four independent measures of the JWST mirror segment pistons (two wavelengths for two sources), agree to within 10~nm to 15~nm, comparable to the expected errors based on an analysis of closure phases on the calibrator star. Including a baseline-based phase correction improves the dynamic range of the final images by about 23\%.

Keywords

Cite

@article{arxiv.2510.13502,
  title  = {A New Method for Aperture Masking Interferometric Imaging: Demonstration with the JWST},
  author = {Christopher Carilli and Bojan Nikolic and Laura Torino and N. Thyagarajan and Ubaldo Iriso},
  journal= {arXiv preprint arXiv:2510.13502},
  year   = {2026}
}

Comments

18 pages, 7 figures, 2 tables, submitted to Optical Engineering (SPIE)

R2 v1 2026-07-01T06:38:51.700Z