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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?

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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"

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2
  • You should either add Linux tag to question, or add Windows solution to answer – nmtoken Nov 19 '20 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 '20 at 21:19

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