PMOIRED - Parametric Modeling of Optical Interferometric Data -
a set of Python3 tools written by Antoine Mérand.
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Abstract (Bibcode:2022ascl.soft05001M):
PMOIRED models astronomical spectro-interferometric data stored in the OIFITS format. Parametric modeling is used to describe the observed scene as blocks such as disks, rings and Gaussians which can be combined and their parameters linked. It includes plotting, least-square fitting and bootstrapping estimation of uncertainties. For spectroscopic instruments (such as GRAVITY), tools are provided to model spectral lines and correct spectra for telluric lines.

Oimodeler - a modular modelling software for optical interferometry -
a set of Python3 tools written by Anthony Meilland et al.
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Extract from the abstract (Bibcode:2024SPIE13095E..2WM):
Oimodeler allows to build complex models from various type of components ranging from simple geometrical to external outputs of radiative transfer models & to add chromaticity (continuum, line and bands) and time-dependence easily.

OITOOLS - the All-in-One Tool Package for Optical Interferometry -
a Julia package written by Fabien Baron.
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OITOOLS allows to fit models to polychromatic or polytemporal data using NLOpt minimizers, to do Bayesian model selection via Nested sampling, and to bootstrap errors.

Binary Grid Search Procedure
a set of IDL routines written by Gail Schaefer.
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The program fits a binary model to interferometric data by searching through a grid of binary positions to find a global solution with the minimum chi squared. At each step in the grid, the code uses mpfit to minimize the binary solution.

CANDID - Companion Analysis and Non-Detection in Interferometric Data -
a set of Python2/3 tools written by Alexandre Galenne and Antoine Mérand.
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Extract from the abstract (Bibcode:2015A&A...579A..68G):
CANDID allows to search systematically for point-source, high-contrast companions and estimate the detection limit using all interferometric observables, i.e., the squared visibilities, closure phases and bispectrum amplitudes. It also incorporates a robust method to set a 3σ detection limit on the flux ratio, which is based on an analytical injection of a fake companion at each point in the grid.

fouriever- for companion detection
a python toolkit written by Jens Kammerer for calibrations, correlations, and companion search for long-baseline interferometry, aperture masking and also kernel phase data.
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fouriever provides, in particular, Chi-squared detection maps similar to the fitMaps in CANDID, but including the possibility to account for correlations.