World Magnetic Model
The World Magnetic Model (WMM) is the standard geomagnetic reference used for navigation, attitude and heading systems worldwide. Produced jointly by NOAA NCEI and the British Geological Survey and sponsored by the U.S. NGA and the U.K. Defence Geographic Centre, the current version (WMM2025) was released on 17 December 2024 and is valid through 31 December 2029.
