[PROJ] What is the syntax for a vertical datum change?

[Ulises Ibarra]

Hello:
I am trying to change the vertical datum of a LIDAR LAS file. But first I
must understand the syntax of proj, but I can't understand it.

If I use the following expression:
echo 747194.732 2307402.892 2037.133 | proj +proj=vgridshift
+grids=C:/clouds/geoids/GGM10_GEO.gtx

I get:
Rel. 9.3.1, December 1st, 2023
<proj>:
can't initialize operations that produce angular output coordinates
program abnormally terminated

So I try to try an operation that seems to be simpler:
>cs2cs +proj=utm +zone=13 +north +ellps=WGS84 +units=m +no_defs
+ellps=wgs84 +to +proj=tmerc +lon_0=-102.624373 +ellps=wgs84

And the result is:
cannot instantiate target coordinate system
program abnormally terminated

I thank you for your kind attention.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/proj/attachments/20240314/128334d0/attachment.htm>