The ArcGIS (or QGIS in qpj) save 3857 in such prj file:
I hoped that this thread could remain focused just about GeoTIFF encoding.
Shapefile encoding issues are a different matter (see
http://trac.osgeo.org/gdal/ticket/3962)
PROJCS["WGS 84 / Pseudo-Mercator",
GEOGCS["WGS 84",
DATUM["WGS_1984",
SPHEROID["WGS 84",6378137,298.257223563,
AUTHORITY["EPSG","7030"]],
AUTHORITY["EPSG","6326"]],
PRIMEM["Greenwich",0,
AUTHORITY["EPSG","8901"]],
UNIT["degree",0.0174532925199433,
AUTHORITY["EPSG","9122"]],
AUTHORITY["EPSG","4326"]],
PROJECTION["Mercator_1SP"],
PARAMETER["central_meridian",0],
PARAMETER["scale_factor",1],
PARAMETER["false_easting",0],
PARAMETER["false_northing",0],
UNIT["metre",1,
AUTHORITY["EPSG","9001"]],
AXIS["X",EAST],
AXIS["Y",NORTH],
EXTENSION["PROJ4","+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0
+lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgrids=@null +wktext
+no_defs"],
AUTHORITY["EPSG","3857"]]
Are you 100% positive that ArcGIS generates such a .prj ? This doesn't look
like classical ESRI WKT (which generally lacks most AUTHORITY nodes and has no
EXTENSION PROJ4 stuff), but like GDAL WKT.
And GDAL opens such shape file and set the spheroid.
But if I save the shape file in 3857 via GDAL I get ellipsoid:
PROJCS["WGS_84_Pseudo_Mercator",
GEOGCS["GCS_WGS_1984",
DATUM["D_WGS_1984",
SPHEROID["WGS_1984",6378137,298.257223563]],
PRIMEM["Greenwich",0],
UNIT["Degree",0.017453292519943295]],
PROJECTION["Mercator"],
PARAMETER["central_meridian",0],
PARAMETER["false_easting",0],
PARAMETER["false_northing",0],
UNIT["Meter",1],
PARAMETER["standard_parallel_1",0.0]]
Yes, that's the result after morphToESRI(). Which is probably not the right
ESRI WKT for WebMercator, anyway... Should rather be something like the
following according to http://trac.osgeo.org/gdal/ticket/3962 :
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_Auxiliary_Sphere"],
PARAMETER["False_Easting",0.0],
PARAMETER["False_Northing",0.0],
PARAMETER["Central_Meridian",0.0],
PARAMETER["Standard_Parallel_1",0.0],
PARAMETER["Auxiliary_Sphere_Type",0.0],
UNIT["Meter",1.0],
AUTHORITY["ESRI","102100"]]
And both GDAL(QGIS) and ArcGIS open this shape file and set the ellipsoid!
I don't understand what you mean here.
