This calculates IGRF corrected version of the magnetic data. It requires, as input, a magnetic dataset for an area as well as a digital elevation model. Since the IGRF correction relates to latitude and longitude, the projection of the input dataset is required.
The choice of projection is obtained through drop boxes.
IGRF Code (Accessed 28 March, 2014, http://www.ngdc.noaa.gov/IAGA/vmod/igrf.html), originally written in FORTRAN, was developed using subroutines written by A. Zunde (USGS), S.R.C. Malin & D.R. Barraclough (Institute of Geological Sciences, United Kingdom). Translated into C by Craig H. Shaffer. Rewritten by David Owens and maintained by: Stefan Maus (NOAA)