[Qgis-user] ogr2ogr - how to use -s_srs, -t_srs and -a_srs

[Andre Joost]

Am 06.08.2017 um 11:07 schrieb Erik Josefsson:

>
> It seems I need an interpreter of the output from ogrinfo that can
> translate that rather complex output into a simple EPSG-code.

gdalsrsinfo has an easier output, but will not reveal EPSG codes either.

One reason is because  many EPSG codes share basically the same 
projection parameters. As an example, EPSG:4258 (ETRS89) and EPSG:4619 
(SWEREF99) are identical. QGIS makes an educated guess, but still does 
not know which one you want.

The other way is easy to implement: gdalsrsinfo EPSG:4619 has a unique 
output of

PROJ.4 : '+proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs '

OGC WKT :
GEOGCS["SWEREF99",
     DATUM["SWEREF99",
         SPHEROID["GRS 1980",6378137,298.257222101,
             AUTHORITY["EPSG","7019"]],
         TOWGS84[0,0,0,0,0,0,0],
         AUTHORITY["EPSG","6619"]],
     PRIMEM["Greenwich",0,
         AUTHORITY["EPSG","8901"]],
     UNIT["degree",0.0174532925199433,
         AUTHORITY["EPSG","9122"]],
     AUTHORITY["EPSG","4619"]]

It even adds the EPSG code as last line to the WKT definition (which 
ESRI software does not do).

HTH,
André Joost