EGM96 and EGM2008 and Other Geoid Grids

 

Geoid models created by NGA as a grid.  These have the height above the ellipsoid in meters, and should range up to approximately 100 m in absolute value.

EGM2008

EGM1996


Using in MICRODEM

The grids are downloaded with the geology download, and then files will be in  available in  C:\mapdata\geology\geology_grids


NAVD88 to other datums: https://vdatum.noaa.gov/download.php#download_geoid  has GTX files

GEOID12B_CONUS

GEOID 18 US


 

GDAL reads a number of the grid shift files needed for the vertical datum shifts:


References


Last revision 6/4/2020