Vertical Datum Transformations

The Geographic Calculator supports transformation between vertical datums and geoid models.  These models are largely based on grid tables and are not easily implemented by the end-user.  If you require a particular vertical model that is not supported, please contact Technical Support to request the model.  For more information on vertical transformations, please see:

Note: When browsing through the datasource some objects may be flagged with a red exclamation point symbol.  These objects are incomplete definitions.  The Geographic Calculator includes a number of datum transformation definitions that require supplementary data files to function properly.  These objects cannot be used until the supplementary files are added.  Some of these are available at our website (http://www.bluemarblegeo.com), while others are proprietary and must be purchased from a specific government agency.