IGRF-13

International Geomagnetic Reference Field (IGRF13) model with object-oriented Python and Matlab interfaces for calculating Earth's magnetic field components.

International Geomagnetic Reference Field: IGRF13 in object-oriented Python or Matlab. The current public Python API and build path target IGRF13; IGRF11 and IGRF12 source files are retained in the repository but are not exposed by the current driver. The software provides calculations of Earth's main magnetic field components (north, east, down, total intensity) as well as magnetic inclination and declination at specified geographic coordinates and altitudes. Secular variation, the annual rate of change of each component in nT/year, can be requested instead of main-field values, and coordinates may be supplied as either geodetic (WGS84 spheroid) or geocentric. It uses a Fortran backend with Python and Matlab interfaces, and outputs results as xarray Datasets for easy integration with other geoscience tools. The included IGRF13 synthesis routine is valid through 2025.0, with reduced-accuracy warnings for later dates.