[gdal-dev] OGRCreateCoordinateTransformation()

[Steve Riddell]

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.rouault at spatialys.com>
Sent: Friday, March 18, 2022 5:05 PM
To: Steve Riddell <sriddell at geocue.com>; gdal-dev at 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
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