2

I recently noticed that all vector and raster files with CRS EPSG:2163 (US National Atlas Equal Area) are being automatically reinterpreted as EPSG:9311. When I load the layers into QGIS initially they are not properly projected, so I must manually update the CRS to EPSG:2163 in QGIS and everything is fine. This is a huge pain so I would like to understand if there are any solutions that don't involve manually setting the projection in QGIS!

Running projinfo suggests that EPSG:9311 is somehow a preferred option to EPSG:2163:

>projinfo "EPSG:2163"

Warning: object is deprecated
Alternative non-deprecated CRS:
  EPSG:9311

PROJ.4 string:
+proj=laea +lat_0=45 +lon_0=-100 +x_0=0 +y_0=0 +ellps=sphere +units=m +no_defs +type=crs

WKT2:2019 string:
PROJCRS["US National Atlas Equal Area",
    BASEGEOGCRS["Unspecified datum based upon the Clarke 1866 Authalic Sphere",
        DATUM["Not specified (based on Clarke 1866 Authalic Sphere)",
            ELLIPSOID["Clarke 1866 Authalic Sphere",6370997,0,
                LENGTHUNIT["metre",1]]],
        PRIMEM["Greenwich",0,
            ANGLEUNIT["degree",0.0174532925199433]],
        ID["EPSG",4052]],
    CONVERSION["US National Atlas Equal Area",
        METHOD["Lambert Azimuthal Equal Area (Spherical)",
            ID["EPSG",1027]],
        PARAMETER["Latitude of natural origin",45,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8801]],
        PARAMETER["Longitude of natural origin",-100,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8802]],
        PARAMETER["False easting",0,
            LENGTHUNIT["metre",1],
            ID["EPSG",8806]],
        PARAMETER["False northing",0,
            LENGTHUNIT["metre",1],
            ID["EPSG",8807]]],
    CS[Cartesian,2],
        AXIS["easting (X)",east,
            ORDER[1],
            LENGTHUNIT["metre",1]],
        AXIS["northing (Y)",north,
            ORDER[2],
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["unknown"],
        AREA["USA"],
        BBOX[15.56,167.65,74.71,-65.69]],
    ID["EPSG",2163]]

I am running QGIS 3.14.16-Pi with GDAL 3.1.3 and PROJ 7.1.1 on Ubuntu 20.04

When I run gdalinfo on one of my rasters I get this output that suggests GDAL is interpreting the CRS as EPSG:9311

Coordinate System is:
PROJCRS["NAD27 / US National Atlas Equal Area",
    BASEGEOGCRS["NAD27",
        DATUM["North American Datum 1927",
            ELLIPSOID["Clarke 1866",6378206.4,294.978698213898,
                LENGTHUNIT["metre",1]]],
        PRIMEM["Greenwich",0,
            ANGLEUNIT["degree",0.0174532925199433]],
        ID["EPSG",4267]],
    CONVERSION["US National Atlas Equal Area",
        METHOD["Lambert Azimuthal Equal Area (Spherical)",
            ID["EPSG",1027]],
        PARAMETER["Latitude of natural origin",45,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8801]],
        PARAMETER["Longitude of natural origin",-100,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8802]],
        PARAMETER["False easting",0,
            LENGTHUNIT["metre",1],
            ID["EPSG",8806]],
        PARAMETER["False northing",0,
            LENGTHUNIT["metre",1],
            ID["EPSG",8807]]],
    CS[Cartesian,2],
        AXIS["easting (X)",east,
            ORDER[1],
            LENGTHUNIT["metre",1]],
        AXIS["northing (Y)",north,
            ORDER[2],
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["unknown"],
        AREA["USA"],
        BBOX[15.56,167.65,74.71,-65.69]],
    ID["EPSG",9311]]

Is the automatic re-assignment from a deprecated EPSG code expected behavior?

When I run gdalinfo on the same file but in a different environment with older versions of GDAL (3.0.4) and PROJ (7.0.0), I get the expected result:

Coordinate System is:
PROJCRS["US National Atlas Equal Area",
    BASEGEOGCRS["Unspecified datum based upon the Clarke 1866 Authalic Sphere",
        DATUM["Not specified (based on Clarke 1866 Authalic Sphere)",
            ELLIPSOID["Clarke 1866 Authalic Sphere",6370997,0,
                LENGTHUNIT["metre",1]]],
        PRIMEM["Greenwich",0,
            ANGLEUNIT["degree",0.0174532925199433]],
        ID["EPSG",4052]],
    CONVERSION["US National Atlas Equal Area",
        METHOD["Lambert Azimuthal Equal Area (Spherical)",
            ID["EPSG",1027]],
        PARAMETER["Latitude of natural origin",45,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8801]],
        PARAMETER["Longitude of natural origin",-100,
            ANGLEUNIT["degree",0.0174532925199433],
            ID["EPSG",8802]],
        PARAMETER["False easting",0,
            LENGTHUNIT["metre",1],
            ID["EPSG",8806]],
        PARAMETER["False northing",0,
            LENGTHUNIT["metre",1],
            ID["EPSG",8807]]],
    CS[Cartesian,2],
        AXIS["easting (X)",east,
            ORDER[1],
            LENGTHUNIT["metre",1]],
        AXIS["northing (Y)",north,
            ORDER[2],
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["unknown"],
        AREA["USA"],
        BBOX[15.56,167.65,74.71,-65.69]],
    ID["EPSG",2163]]

As far as I can tell the only difference between the two CRS' is the datum:

  • EPSG:2163 : "Not specified (based on Clarke 1866 Authalic Sphere)"
  • EPSG:9311 : "North American Datum 1927"

Does anyone know what GDAL and PROJ do with the deprecated CRS warning? Or why the files would be automatically re-interpreted with a different CRS?

Improve this question

1 Answer 1

Reset to default
0

While it appears that there are deeper problems lurking with EPSG:2163, it is possible to prevent the automatic re-assignment of the CRS by setting the environment variable OSR_USE_NON_DEPRECATED to NO in the startup script:

add this line to ~/.bashrc:

export OSR_USE_NON_DEPRECATED=NO

GDAL (and therefore QGIS) will respect this setting and allow you to load layers projected in a deprecated CRS!

Full response from Even Rouault on the PROJ user mailing list on November 5, 2020:

"As far as I remember regarding the deprecation of EPSG:2163, I noticed in a recent EPSG release that the underlying datum of EPSG:2163 which is EPSG:4052 "Unspecified datum based upon the Clarke 1866 Authalic Sphere" was now deprecated, but EPSG:2163 was still non-deprecated, which isn't very logical. IOGP conclusion was that EPSG:2163 had to be deprecated, and they created EPSG:9311 as the future proof CRS.

The automated substitution is done by GDAL OGRSpatialReference::ImportFromEPSG() method. I admit this may be a bit surprising. If I remember well, this was to emulate a past GDAL behaviour where some deprecated Italian CRS had an override in the .csv files GDAL handled to "fix" it to have an equivalent definition of the non-deprecated newer CRS. The cleanest way with the now PROJ mechanism was to identify the non-deprecated version of a deprecated CRS instead, but I can see this is not always desirable.

You can opt out for that automatic substituion by setting the OSR_USE_NON_DEPRECATED environment variable to NO"

Improve this answer
2
  • You should either add Linux tag to question, or add Windows solution to answer
    – nmtoken
    Nov 19, 2020 at 18:34
  • I added linux tag, if someone can provide details on how to set the environment variable in Windows then I can update post accordingly.
    – Henry Rodman
    Nov 20, 2020 at 21:19

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.