GeoidLab: An automated open-source Python toolbox for gravity-field analysis and vertical datum unification

GeoidLab is an open-source, modular Python package designed to automate high-accuracy regional geoid computation and gravity-field analysis, addressing barriers in existing tools such as manual preprocessing and steep learning curves. By integrating APIs for on-demand retrieval of global geopotential models from ICGEM and digital elevation models from sources like SRTM and Copernicus, GeoidLab streamlines the remove-compute-restore workflow. Key features include spherical harmonic synthesis of gravity functionals, terrain corrections (e.g., primary/secondary indirect topographic effects, residual terrain modeling), gravity reductions (free-air, Bouguer, Poincaré-Prey), and Stokes’ integral with modifications (Meissl, Wong & Gore, Heck & Grüninger). Workflows are configuration-driven via a single file and executed through a unified command-line interface, reducing manual steps by over 95% and enabling publication-grade outputs. Validation over benchmark regions like Auvergne (France) and Ghana yields sub-3 cm RMS precision, consistent with literature. GeoidLab supports vertical datum unification tasks and serves as an educational tool through reusable modules and Jupyter tutorials, promoting reproducible geodesy for researchers, students, and practitioners.