Vertical Grid Shift Files

In order to perform vertical datum transforms (other than Local Ellipsoid Height transformations), you must first have the appropriate grid shift files. You can download these files directly from the Blue Marble Geographics website (www.bluemarblegeo.com). This is a self-installing file. By default, these files will be installed to the "...\Blue Marble Geo\Geographic Calculator 7.0\Data\shiftfiles\vertical" directory.

If you choose to move the ".../Data/Shiftfiles/vertical/" directory, you must specify the path, in the Calculator, to the directory where the vertical grid shift files reside.  This can be set under Options>Preferences>File Locations.