Custom coordinate system recognition error

[jiaxiaoniu]

wkt is defined in ArcGIS.
wkt is：

        PROJCS["WGS_1984_Web_Mercator_Auxiliary_Sphere",
    GEOGCS["GCS_WGS_1984",
        DATUM["D_WGS_1984",
            SPHEROID["WGS_1984", 6378137.0, 298.257223563]
        ],
        PRIMEM["Greenwich", 0.0],
        UNIT["Degree", 0.0174532925199433]
    ],
    PROJECTION["Mercator"],
    PARAMETER["False_Easting", 0.0],
    PARAMETER["False_Northing", 0.0],
    PARAMETER["Central_Meridian", 0.0],
    PARAMETER["Standard_Parallel_1", 0.0],
    UNIT["Meter", 1.0]
]

This coordinate system is correctly recognized in ArcGIS Pro, but in the .proj file it will be recognized as epsg:3857.

[jjimenezshaw]

What is the problem?

[jiaxiaoniu]

What is the problem?

When data from this coordinate system is overlaid with EPSG:3857 data, an offset occurs. I suspect that ArcGIS uses the Mercator projection method to define the coordinate system, which is based on an ellipsoid, while EPSG:3857 is based on a sphere. The project file likely incorrectly identifies the coordinate system as EPSG:3857.

[busstoptaktik]

EPSG:3857 is based on a sphere.

@jiaxiaoniu The base CRS for EPSG:3857 (WGS84/Pseudo Mercator) is EPSG:4326, i.e. geographic 2D latitude/longitude, based on the WGS84 datum ensemble (EPSG:6326), using the WGS84 ellipsoid.

The projection ("conversion") used, however, is a spherical Mercator, i.e. the "Popular Visualisation Pseudo-Mercator" (EPSG:3856)

Hence your "based on a sphere" description only applies to the projection, as also hinted at by the auxiliary sphere part of the first line of the WKT you provide. The corresponding geographical coordinates are assumed to be ellipsoidal.

[jjimenezshaw]

As you can see in https://jjimenezshaw.github.io/Esri-codes-analyzer/deprecated.html
the system ESRI:102100 WGS_1984_Web_Mercator_Auxiliary_Sphere is deprecated in favour of EPSG:3857

That webpage is just procesing data from ESRI from https://github.com/Esri/projection-engine-db-doc/

[jiaxiaoniu]

Thanks! I’ll try to resolve my current issue based on this.