[gdal-dev] gdaltransform question

[Even Rouault]

On mercredi 9 octobre 2019 18:28:40 CEST McLane, Kathleen A ERDC-RDE-GRL-VA 
CIV wrote:
> Hello,
> 
> I'm using gdaltransform to transform points from one datum to WGS84. In
> version 2.2.3 and 2.4.0 of GDAL, when I convert a point I receive a
> transformed latitude, longitude, and a new height value. In versions 2.4.1
> and 3.0.1, when I convert a point I receive a transformed latitude and
> longitude but height always equals 0. Attached are examples of the height
> value issue. Is this a GDAL error, or am I doing something wrong?

Your examples show more a difference at the PROJ level, but indeed there have 
been changes in PROJ 6 where doing a transformation between geographic CRS 
only cause 2D corrections to be applied, as this is what is recommended by 
EPSG. If you want corrections on ellipsoidal heights as well, you have to 
operate in the geocentric coordinate domain.

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