Thanks very much, Even. For reporting the problem, I “packaged up” a case with CRS’s with EPGS codes. For the actual problem I’m working, the target CRS is a custom projection –no EPSG.
From: Even Rouault <even.roua...@spatialys.com> Sent: Friday, March 18, 2022 5:05 PM To: Steve Riddell <sridd...@geocue.com>; gdal-dev@lists.osgeo.org Subject: Re: OGRCreateCoordinateTransformation() Steve, Fix in PROJ queued in https://github.com/OSGeo/PROJ/pull/3123 The complexity of dealing with legacy features TOWGS84[] and PROJ4_GRIDS is highly stressing PROJ pipeline computation engine. Using the plain EPSG codes EPSG:4955 -> EPSG:4617+5713 would be much preferable here Even Le 18/03/2022 à 21:14, Steve Riddell a écrit : Hi, I’m getting an error (below) using GDAL trying to set up a transformation between NAD83(CSRS) geodetic, w/ ellipsoidal heights, and NAD83(CSRS) geodetic, CGVD28 heights. Similar transformations work fine on some datums, but fail on others. Hope someone can offer some insight. Note the if I don't use the PROJ4_GRIDS extension, I don't get the error, but I don't get the geoid adjustment either. COMPD_CS["NAD83(CSRS) + Ellipsoid (Meters)", GEOGCS["NAD83(CSRS)", DATUM["NAD83_Canadian_Spatial_Reference_System", SPHEROID["GRS 1980",6378137,298.257222101, AUTHORITY["EPSG","7019"]], TOWGS84[0,0,0,0,0,0,0], AUTHORITY["EPSG","6140"]], PRIMEM["Greenwich",0, AUTHORITY["EPSG","8901"]], UNIT["degree",0.0174532925199433, AUTHORITY["EPSG","9122"]], AUTHORITY["EPSG","4617"]], VERT_CS["Ellipsoid (Meters)", VERT_DATUM["Ellipsoid",2002], UNIT["metre",1, AUTHORITY["EPSG","9001"]], AXIS["ellipsoidal height",UP]]] COMPD_CS["NAD83(CSRS) + CGVD28 height - HT2_0", GEOGCS["NAD83(CSRS)", DATUM["NAD83_Canadian_Spatial_Reference_System", SPHEROID["GRS 1980",6378137,298.257222101, AUTHORITY["EPSG","7019"]], TOWGS84[0,0,0,0,0,0,0], AUTHORITY["EPSG","6140"]], PRIMEM["Greenwich",0, AUTHORITY["EPSG","8901"]], UNIT["degree",0.0174532925199433, AUTHORITY["EPSG","9122"]], AUTHORITY["EPSG","4617"]], VERT_CS["CGVD28 height - HT2_0", VERT_DATUM["Canadian Geodetic Vertical Datum of 1928",2005, EXTENSION["PROJ4_GRIDS","HT2_0.gtx"], AUTHORITY["EPSG","5114"]], UNIT["metre",1, AUTHORITY["EPSG","9001"]], AXIS["Gravity-related height",UP], AUTHORITY["EPSG","5713"]]] ERROR 6: Cannot find coordinate operations from `EPSG:4955' to `COMPOUNDCRS["NAD83(CSRS) + CGVD28 height - HT2_0",BOUNDCRS[SOURCECRS[GEOGCRS["NAD83(CSRS)",DATUM["NAD83 Canadian Spatial Reference System",ELLIPSOID["GRS 1980",6378137,298.257222101,LENGTHUNIT["metre",1]]],PRIMEM["Greenwich",0,ANGLEUNIT["degree",0.0174532925199433]],CS[ellipsoidal,2],AXIS["geodetic latitude (Lat)",north,ORDER[1],ANGLEUNIT["degree",0.0174532925199433]],AXIS["geodetic longitude (Lon)",east,ORDER[2],ANGLEUNIT["degree",0.0174532925199433]],ID["EPSG",4617]]],TARGETCRS[GEOGCRS["WGS 84",DATUM["World Geodetic System 1984",ELLIPSOID["WGS 84",6378137,298.257223563,LENGTHUNIT["metre",1]]],PRIMEM["Greenwich",0,ANGLEUNIT["degree",0.0174532925199433]],CS[ellipsoidal,2],AXIS["latitude",north,ORDER[1],ANGLEUNIT["degree",0.0174532925199433]],AXIS["longitude",east,ORDER[2],ANGLEUNIT["degree",0.0174532925199433]],ID["EPSG",4326]]],ABRIDGEDTRANSFORMATION["Transformation from NAD83(CSRS) to WGS84",METHOD["Position Vector transformation (geog2D domain)",ID["EPSG",9606]],PARAMETER["X-axis translation",0,ID["EPSG",8605]],PARAMETER["Y-axis translation",0,ID["EPSG",8606]],PARAMETER["Z-axis translation",0,ID["EPSG",8607]],PARAMETER["X-axis rotation",0,ID["EPSG",8608]],PARAMETER["Y-axis rotation",0,ID["EPSG",8609]],PARAMETER["Z-axis rotation",0,ID["EPSG",8610]],PARAMETER["Scale difference",1,ID["EPSG",8611]]]],BOUNDCRS[SOURCECRS[VERTCRS["CGVD28 height - HT2_0",VDATUM["Canadian Geodetic Vertical Datum of 1928"],CS[vertical,1],AXIS["gravity-related height",up,LENGTHUNIT["metre",1]],ID["EPSG",5713]]],TARGETCRS[GEOGCRS["WGS 84",DATUM["World Geodetic System 1984",ELLIPSOID["WGS 84",6378137,298.257223563,LENGTHUNIT["metre",1]]],PRIMEM["Greenwich",0,ANGLEUNIT["degree",0.0174532925199433]],CS[ellipsoidal,3],AXIS["latitude",north,ORDER[1],ANGLEUNIT["degree",0.0174532925199433]],AXIS["longitude",east,ORDER[2],ANGLEUNIT["degree",0.0174532925199433]],AXIS["ellipsoidal height",up,ORDER[3],LENGTHUNIT["metre",1]],ID["EPSG",4979]]],ABRIDGEDTRANSFORMATION["CGVD28 height - HT2_0 to WGS84 ellipsoidal height",METHOD["GravityRelatedHeight to Geographic3D"],PARAMETERFILE["Geoid (height correction) model file","HT2_0.gtx",ID["EPSG",8666]]]]]' Thanks in advance for any assistance! Best regards, Steve Steve Riddell Software Engineering GeoCue Group, Inc. 520 6th Street | Madison, AL 35756 USA Phone: 256.461.8289 | Fax: 256.461.8249 LIDAR/Drone Mapping Software & Services – True View® 3D Imaging Sensors – Image/LIDAR Data Management Solutions www.geocue.com<http://www.geocue.com/> support.geocue.com<https://support.geocue.com/> -- http://www.spatialys.com My software is free, but my time generally not.
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