I have measurement data that uses X/Y in different zones of JGD2011 and an ellipsoid height above GRS1980 (but it also includes a geoid height as well). My task is to transform this data to "WGS84 LLA".

For the horizontal part I used a transform from (for example) EPSG:6677 to EPSG:4326, and all seems well. However, I am really confused what to do with the height (and whether I even need to do something).

The WGS84 and GRS80 ellipsoids seem to differ, but I was unable to find out by how much, and how to convert the data.

I tried a conversion from EPSG:6667 to EPSG:4979 with adjusted input data, but the result is a noop, so maybe there is no difference after all.

So my question is: how should I handle the height? I am not even sure if I should output the ellipsoid height or geoid height, WGS84 also includes a geoid definition ...?

  • What accuracy is your data? You may want to run some checks on how different the geoid models are in your area of interest. – mkennedy Aug 22 at 16:55
  • @mkennedy The data has centimeter-level precision. I will use the ellipsoid height, but I have read their origins vary by 2m, so the height may be shifted. – mwil.me Aug 23 at 3:48

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