[Gdal-dev] RE: Newbie (ogr2ogr reprojecting NZMG to NZTM)

[Jeremy Palmer]

Hi Andrew,
 
Looks like ogr2ogr and ogrinfo is building the wrong datum WKT string.
I've even tried transforming a test shape file and the .prj file
produced had an incorrect WKT projection definition:

i.e
ogr2ogr -f "ESRI Shapefile" crs_node_nztm.shp crs_node.shp -a_srs
"+proj=nzmg +lat_0=-41 +lon_0=173 +x_0=2510000 +y_0=6023150 +ellps=intl
+datum=nzgd49 +units=m +no_defs <> +nadgrids=nzgd2kgrid0005.gsb +wktext"
-t_srs EPSG:2193

crs_node_nztm.prj =

PROJCS["NZGD2000 / New Zealand Transverse Mercator",
   GEOGCS["NZGD2000",
        DATUM["D_",
           SPHEROID["GRS_1980",6378137,298.257222101]],
           PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",173],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",1600000],
    PARAMETER["false_northing",10000000],
    UNIT["Meter",1]]

This is the WKT information from postgis which looks like it has the
correct definition (don't worry about the AUTHORITY references).

"PROJCS["NZGD2000 / New Zealand Transverse Mercator",
   GEOGCS["NZGD2000",
       DATUM["New_Zealand_Geodetic_Datum_2000",
          SPHEROID["GRS
1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],
      TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6167"]],
      PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],
      UNIT["degree",0.01745329251994328, AUTHORITY["EPSG","9122"]],
AUTHORITY["EPSG","4167"]],
   PROJECTION["Transverse_Mercator"],
  
PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",173],
  
PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",1600000],
   PARAMETER["false_northing",10000000],
   UNIT["metre",1,AUTHORITY["EPSG","9001"]],AUTHORITY["EPSG","2193"]]"

The actual transformation of the shapefiles seems good, as I've
compared some test against a couple of datasets which were transformed
using our own tools.

Cheers
Jeremy


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