eht-imaging is a Python package for simulating, analyzing, and imaging very long baseline interferometry (VLBI) data.
The package addresses the challenge of reconstructing astronomical images from radio interferometric observations, which measure data in the frequency domain rather than as direct images. It provides tools to load and simulate VLBI data with realistic antenna tracks, calibrate observations, and reconstruct images using regularized maximum likelihood methods. The core functionality centers on several primary classes: Image and Movie for handling image data, Array and Obsdata for managing telescope configurations and observations, Imager for the reconstruction process, and Caltable for calibration information. Users can work with various polarizations, apply different data terms and regularizing functions, and inspect or plot data at multiple stages.
The tool is suited for radio astronomers and interferometry researchers working with VLBI datasets who need to simulate observations, test imaging algorithms, or produce publication-quality reconstructions. It handles the full pipeline from raw visibility data through calibration to final image products. The package is particularly relevant for projects involving complex imaging scenarios where standard Fourier inversion is insufficient. A major revision is under active development on the dev branch, which replaces the older pyNFFT dependency with the actively maintained finufft library for Fourier transforms, addressing compatibility constraints in the stable release.
The project maintains a stable release on PyPI with straightforward pip installation, though users requiring fast Fourier transform functionality must separately install NFFT and its wrapper. The dev branch represents ongoing modernization of the codebase to resolve dependency limitations. The package is documented with a stable documentation site and carries a DOI for citation in scientific work. Issues and pull requests are welcomed, with direct contact available for users needing application-specific assistance.
