[MetaCRS] Coordinate offset after transformation from 4267 to 4326

[Betsy Emmons]

Hello,

I'm using Proj.4 v4.9.1 and GeoTools v13.x. When a WMS layer is brought
into QGIS as EPSG:4326 there is a noticeable offset compared to the same
local layer. The WMS layer source is EPSG:4267.

A WMS 4326 sample point has a coordinate of -97.2341220, 28.0611696 and the
same local 4326 sample point has a coordinate of -97.2339531, 28.0608752.
This is roughly a 40m difference. Some local calculations have shown the
error margin to be <=111m.

Here is the source 4267 projection
definition: GEOGCS["GCS_North_American_1927",DATUM["D_North_American_1927",SPHEROID["Clarke_1866",6378206.4,294.9786982]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]].

Here's what geotools is using:
GEOGCS["NAD27",
  DATUM["North American Datum 1927",
    SPHEROID["Clarke 1866", 6378206.4, 294.9786982138982,
AUTHORITY["EPSG","7008"]],
    TOWGS84[2.478, 149.752, 197.726, 0.526, -0.498, 0.501, 0.685],
    AUTHORITY["EPSG","6267"]],
  PRIMEM["Greenwich", 0.0, AUTHORITY["EPSG","8901"]],
  UNIT["degree", 0.017453292519943295],
  AXIS["Geodetic longitude", EAST],
  AXIS["Geodetic latitude", NORTH],
  AUTHORITY["EPSG","4267"]]

Proj.4 is really a great library! Thank you for maintaining and
contributing to it!

Thank you,
Betsy Emmons


Betsy Emmons
Community Support Manager | Boundless <http://boundlessgeo.com/>
*bemmons at boundlessgeo.com <bemmons at boundlessgeo.com>*
908.208.9692 <908-208-9692>
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