SAMpy: a Fourier-plane pipeline for JWST/NIRISS aperture masking interferometry (and more!)

The JWST Early Release Science Program 1386: "High Contrast Imaging of Exoplanets and Exoplanetary Systems includes a NIRISS aperture masking interferometry (AMI) component to demonstrate achievable contrast in a deep observation. As part of this program, we have developed SAMpy: data reduction tools tailored for NIRISS AMI, which are also flexible enough for arbitrary masking setups (e.g. LBT/LMIRCam, Keck/NIRC2, VLT/SPHERE). SAMpy takes a Fourier-plane approach to processing AMI data, which we describe here. We detail the individual pipeline steps, including image pre-processing, calculation and calibration of Fourier observables, OIFITS file generation, and model fitting. We also demonstrate SAMpy on NIRISS commissioning observations of the AB Dor system.