Introduction
FME can reproject data vertically (height) as well as horizontally. FME includes several reprojector transformers; each has its own functionality based on the spatial location of your data. For an in-depth look at these transformers and more information on coordinate systems, please see Working with Coordinate Systems in FME.
If you are looking to reproject vertical datums, there are four transformers: CsmapReprojector, GridInQuestIIReprojector, ReframeReprojector, and EsriReprojector.
Vertical Reprojection Transformers
EsriReprojector
FME supports vertical datum reprojections. Start by selecting the same horizontal source and destination coordinate system, then enable the Vertical section. Next, select the source and destination coordinate system. For more information, see the documentation.
CsmapReprojector
The CsmapReprojector reprojects feature coordinates from one coordinate system to another using the CS-MAP library. The CS-Map library is FME’s default library and is generally used for most transformations, unless other library-specific transformers are used, such as the EsriReprojetor. Using this transformer explicitly ensures the library is used and provides options for handling Z (vertical) values. For an in-depth look at the vertical transformation parameters, please see the documentation.
GridInQuestIIReprojector
The GridInQuestIIReprojector transformer can transform heights in Z values for Ireland, Malin Head, or Belfast. The GridInQuestIIReprojector uses the Grid InQuest library, which is different from FME’s default CS-MAP library. For more information on the GridInQuestIIReprojector, please see the documentation.
ReframeReprojector
The ReframeReprojector reprojects feature coordinates from one coordinate system to another in Switzerland, using the Reframe library from the Federal Office of Topography (swisstopo). It supports typical planimetric and altimetric reference frame changes for Switzerland. For more information on the supported reference frames, please see the documentation.
Additional Resources
[Blog] Heights in Coordinate Systems
[Article] Creating Vertical Adjustment Grid files for use with FME