I have a number of files in Maryland State-Plane (US foot) that have the following wkt:

SPHEROID["GRS 1980",6378137,298.2572221010002,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6269"]],  
UNIT["US survey foot",0.3048006096012192,AUTHORITY["EPSG","9003"]]]

OGRSpatialReference::autoIdentifyEPSG fails to recognize this. As far as I can tell, the only difference in this wkt and the one for 2248 on spatialreference.org is some trailing significant digits, some omitted Authority codes, and a reversal in the order of the standard parallels.

[Edit] I've been looking at the pcs.csv file and while I don't know exactly how to read the columns, it appears that the parameters in the file for 2248 don't match the above wkt or the wkt on spatialreference.org. The standard parallels differ, as does the latitude of origin. This ups the ante on what the right action is.

What is the preferred method for adding this to the data files so that it will be recognized? Do I edit my pcs.csv file? The pcs.override.csv? Or something else? Changing the content of the file is impractical in this case.

  • The data in pcs.csv is in degrees.minutes (as stated by the following value EPSG:9110), while WKT uses decimal degrees. – AndreJ Jun 27 '13 at 8:12
  • thanks, that explains the differences in the values, but why doesn't autoIdentifyEPSG match then? I flipped the order of the parallels in the psc.csv file and that made no difference. – Llaves Jun 27 '13 at 14:06
  • This site prj2epsg.org/search is able to detect the right EPSG code. I don't know how they did it ... See gis.stackexchange.com/questions/7608/… for more details – AndreJ Jun 27 '13 at 14:39

It turns out that GDAL uses the pcs.csv file to go from EPSG to a spatial ref. It is not used to look up the EPSG from a WKT. autoIdentifyEPSG mostly looks for an authority code in a WKT. That's why I couldn't convert my WKT to EPSG.

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