Take the 2-minute tour ×
Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It's 100% free, no registration required.

My projection is this: NAD 1983 StatePlane North Carolina FIPS 3200 Feet, which has a proj4 string that looks like this:

+proj=lcc +lat_1=34.33333333333334 +lat_2=36.16666666666666 +lat_0=33.75 +lon_0=-79 +x_0=609601.2199999999 +y_0=0 +ellps=GRS80 +datum=NAD83 +to_meter=0.3048006096012192 +no_defs

Its SRID is 102719. I've tried to create a db column in PostGIS with an srid option for this projection, but its rejecting the srid, calling it invalid.

I've found a similar projection with a valid srid code, NAD83 / North Carolina (ftUS) (srid=2264), which has a proj4 string nearly identical to the above:

+proj=lcc +lat_1=36.16666666666666 +lat_2=34.33333333333334 +lat_0=33.75 +lon_0=-79 +x_0=609601.2192024384 +y_0=0 +ellps=GRS80 +datum=NAD83 +to_meter=0.3048006096012192 +no_defs 

As you can see, the only difference between these two is that the lat_1 and lat_2 degrees are swapped. They even use the same three degrees, only the first two are differently ordered.

Can I use this second projection?

UPDATE: The answer seems to be leaning towards 'yes', I just ran projection-to-projection transformations from a single projection to the NC projection using the "legitimate" and "illegitimate" proj4's and got similar results down to the 7th decimal place

share|improve this question

1 Answer 1

up vote 2 down vote accepted

You have an ESRI projection (ESRI:102719) however PostGIS (and everyone else but ESRI) are expecting EPSG:2264 (or possibly EPSG:3359 or EPSG:3632). You can use the ESRI one (just be aware that this will not interoperate well with others) - just run the following:

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 9102719, 'esri', 102719, '+proj=lcc +lat_1=34.33333333333334 +lat_2=36.16666666666666 +lat_0=33.75 +lon_0=-79 +x_0=609601.2199999999 +y_0=0 +ellps=GRS80 +datum=NAD83 +to_meter=0.3048006096012192 +no_defs ', 'PROJCS["NAD_1983_StatePlane_North_Carolina_FIPS_3200_Feet",GEOGCS["GCS_North_American_1983",DATUM["North_American_Datum_1983",SPHEROID["GRS_1980",6378137,298.257222101]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Lambert_Conformal_Conic_2SP"],PARAMETER["False_Easting",2000000.002616666],PARAMETER["False_Northing",0],PARAMETER["Central_Meridian",-79],PARAMETER["Standard_Parallel_1",34.33333333333334],PARAMETER["Standard_Parallel_2",36.16666666666666],PARAMETER["Latitude_Of_Origin",33.75],UNIT["Foot_US",0.30480060960121924],AUTHORITY["EPSG","102719"]]');
share|improve this answer
    
I'm getting an error when trying to do this: ERROR: new row for relation "spatial_ref_sys" violates check constraint "spatial_ref_sys_srid_check" DETAIL: Failing row contains (9102719, esri, 102719, PROJCS["NAD_1983_StatePlane_North_Carolina_FIPS_3200_Feet",GEOGC..., +proj=lcc +lat_1=34.33333333333334 +lat_2=36.16666666666666 +lat...). –  boulder_ruby Aug 27 '13 at 15:45
    
Its looking like there is an srid constraint limiting the srid number to < 998999, the one from spatialreference.org is well over that limit -- lists.osgeo.org/pipermail/postgis-users/2012-July/034723.html –  boulder_ruby Aug 27 '13 at 15:47
    
I've changed the srid from 9102719 to 102719, which makes sense because that's what spatialreference.org says the srid is, even though their insert statement mentions the number w/ the 9 in front of it. I think this problem is solved but I'll post if there's any issue –  boulder_ruby Aug 27 '13 at 15:50
    
I'm still getting an invalid SRID code error even after updating spatial_ref_sys.... PG::RaiseException: ERROR: AddGeometryColumn() - invalid SRID –  boulder_ruby Aug 27 '13 at 15:54
3  
I work at Esri. We added 102719 because at the time, EPSG didn't have the NAD83 feet-based state plane zones. We then 'changed the code' to 2264 to match EPSG a LONG time ago, in 9.0 around 2004. –  mkennedy Aug 27 '13 at 16:34

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.