GGXF (Geodetic data Grid eXchange Format) Transformations – Global Mapper

1This function has been added as part of the NOAA National Geodetic Survey NSRS and Canadian Geodetic Survey CSRS modernization (e.g. NATRF2022); see NGS Beta Products for more information.

Developed by the Open Geospatial Consortium (OGC) and the International Association of Geodesy (IAG), the Geodetic Grid Exchange Format (GGXF) is an open, NetCDF-4-based standard designed to store and exchange gridded geodetic data. Serving as the modern replacement for legacy grid formats such as NTv2 (.gsb), NADCON (.las/.los), and traditional NGS binary grids (.bin), GGXF provides a unified container for grid-based transformations and height conversions. Applies geographic coordinate shifts (2D/3D), vertical transformations (using geoid height models like GEOID2022), surface gravity fields, and deflections of the vertical. Can also handle time-dependent models to account for tectonic plate motion and crustal deformation.

GGXF Horizontal Datum Transformations implemented in Geographic Calculator:

GGXF Deformation Model
GXF Geographic 2D Offsets
GGXF 3D Offsets
GGXF Velocity Grid

For geoid implementation, see Geoids.

For more information, see GGXF Standard – Geodetic Data Grid Exchange Format.

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 are not able to be used until the supplementary files are added. Some of these are available at our website (https://www.bluemarblegeo.com), while others are proprietary and must be purchased from a specific government agency.