Earth Magnetic Anomaly Grid (EMAG2)
As reflected in the name the resolution has been improved from 3 arc minute to 2 arc minute and the altitude has been reduced from 5 km to 4 km above geoid. Additional grid and trackline data have been included, both over land and the oceans. Interpolation between sparse tracklines in the oceans was improved by directional gridding and extrapolation, based on an oceanic crustal age model . The longest wavelengths (larger than 330 km) were replaced with the latest CHAMP lithospheric field model MF6.
See the Earth Magnetic Anomaly Grid (EMAG2) add-on page for more details.