Convert XYZ file with WGS84 Ellipsoid elevations to EGM96 Geoid elevations

Question

I have multiple files in XYZ format in UTM horizontal + WGS84 ellipsoid vertical that I need to convert to UTM horizontal EGM96 geoid elevations. There are about 250'000 points in a an area that is 3km on 25km approximately. The points mostly bathymetry points located 5cm to 1m from each other so sampling a raster DEM will not work.

Is there a way do that using gdal, python script, Qgis or Arcgis ?

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What I found so far:

• The NGA's page where one can get EGM96 elevations from lat/long coordinates but that only works one point at a time.
• EPSG:10084 seems to provide transformation from WGS84 to EGM96 but I couldn't find how to use it.

Answer 1

The United States National Oceanic and Atmospheric Administration distributes a freeware package called vDatum for doing vertical datum transformations. vDatum is a Java executable file so there are some installation steps and dependent software (like the appropriate version of Java).

vDatum will accept a text file as input.

Here is a link to the User Guide.

Her is a link to th Datum tutorial.

Sin you asked about GDAL or Python you might be intrested in Using vDatum at the command line.