On Sat, Mar 24, 2012 at 5:18 AM, Stefan Sylla <stefansylla at gmx.de> wrote: > EGM96 (I guess somethin' like 'Earth Geodetic Model') refers to the > vertical datum. FWIW, you can find a gridded version of the EGM2008 here http://grass.osgeo.org/wiki/Global_datasets#EGM2008_Geoid_Data_.28Earth_Gravitational_Model.29 Markus