The following works just fine using cs2cs.
$ echo 16.582941335 47.710445103 291.7692| cs2cs -f "%.3f" +init=epsg:4326 +to +proj=somerc +lat_0=47.14439372222222 +lon_0=19.04857177777778 +k_0=0.99993 +x_0=650000 +y_0=200000 +ellps=GRS67 +nadgrids=etrs2eov_notowgs.gsb +geoidgrids=geoid_eht2014.gtx +units=m +no_defs
However, the same transformation fails in PostGIS.
$ psql -d db -c "SELECT ST_AsEWKT(ST_Transform(ST_GeomFromText('POINT(16.582941335 47.710445103 291.7692)', 4326), '+proj=somerc +lat_0=47.14439372222222 +lon_0=19.04857177777778 +k_0=0.99993 +x_0=650000 +y_0=200000 +ellps=GRS67 +nadgrids=etrs2eov_notowgs.gsb +geoidgrids=geoid_eht2014.gtx +units=m +no_defs'))"
ERROR: proj_crs_is_swapped: proj_crs_get_coordinate_system returned NULL
CONTEXT: SQL function "st_transform" statement 1
Interestingly, if I omit either +geoidgrids or +nadgrids ST_Transform doesn't throw an error, but the coordinates are off.
$ psql -d db -c "SELECT ST_AsEWKT(ST_Transform(ST_GeomFromText('POINT(16.582941335 47.710445103 291.7692)', 4326), '+proj=somerc +lat_0=47.14439372222222 +lon_0=19.04857177777778 +k_0=0.99993 +x_0=650000 +y_0=200000 +ellps=GRS67 +geoidgrids=geoid_eht2014.gtx +units=m +no_defs'))"
st_asewkt
-----------------------------------------------------------------
POINT(465007.88411299663 265848.07307208166 246.45166349798842)
(1 row)
$ psql -d db -c "SELECT ST_AsEWKT(ST_Transform(ST_GeomFromText('POINT(16.582941335 47.710445103 291.7692)', 4326), '+proj=somerc +lat_0=47.14439372222222 +lon_0=19.04857177777778 +k_0=0.99993 +x_0=650000 +y_0=200000 +ellps=GRS67 +nadgrids=etrs2eov_notowgs.gsb +units=m +no_defs'))"
st_asewkt
------------------------------------------------------
POINT(465092.51654231607 265877.1140839074 291.7692)
(1 row)
This suggests that I can work around the problem by using a 2-step approach, but I'd like to aviod that if possible.
What am I doing wrong?
I'm using the PostGIS docker conainter.
$ psql -d db -c "SELECT PostGIS_Full_Version();"
postgis_full_version
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------
POSTGIS="3.1.0dev 50b1e70" [EXTENSION] PGSQL="120" GEOS="3.9.0dev-CAPI-1.14.0" PROJ="7.2.0" LIBXML="2.9.4" LIBJSON="0.12.1" LIBPROTOBUF="1.3.1" WAGYU="0.5.0 (Internal)"
(1 row)
The geiod model and the grid is available here.