The World Magnetic Model and Associated Software
This site provides access to the DoD software and current WMM model and WMM online calculator. The software computes the main components of the geomagnetic field and their annual changes. The programs are designed to be used in demand mode. The software is available as both C and Fortran source code. The model file, WMM.COF, is expected to reside in the same directory as the software. Note: The altitude is referenced to the World Geodetic System 1984 (WGS 84) ellipsoid. The new WMM software library provides functions to convert height above mean sea level (AMSL) to height above WGS 84. This option is enabled by default.
- Input And Output
The input parameters and valid entries are:
- Latitude -90.00 to +90.00 degrees
Longitude -180.00 to +180.00 degrees
referenced to the WGS 84 ellipsoid OR the Mean Sea Level (MSL) (downloadable software)
Date 2010.0 to 2015.0
The seven magnetic components computed are:
- F - Total Intensity of the geomagnetic field
H - Horizontal Intensity of the geomagnetic field
X - North Component of the geomagnetic field
Y - East Component of the geomagnetic field
Z - Vertical Component of the geomagnetic field
I (DIP) - Geomagnetic Inclination
D (DEC) - Geomagnetic Declination (Magnetic Variation)
Annual change in each of these magnetic components is also displayed. The annual
change is computed by subtracting the main field values for the desired input date
from main field values one year later. The output units are displayed using the
abbreviations nT (nanoTesla), deg (degrees) and min (minutes) per year.
Third party software for World Magnetic Model
Third party software is available here. Note: Neither the authors nor
NGDC can provide any warranty or technical support for these programs.
As changes are made to the WMM code, the revised code will be posted.
Check this site for change notices. The downloadable code is always the latest version.
Download the World Magnetic Model - WMM2010 - software and documentation.