I have a Point

RW     HW     EPSG

which ST_Transform transforms into projection EPSG=4326, Lat;Lon 48.2086988651298;16.3686458354975

However, when using http://cs2cs.mygeodata.eu/ and checking with Google Maps and openstreetmap, the actual result should be 48.2087130847;16.3726546685;

This is much to inaccurate.

Am I doing sthg wrong when using Transform?

EDIT1: That's the way I use it:

select ST_Y(a.b), ST_X(a.b) from
  (select ST_Transform(ST_SetSRID(ST_MakePoint(3011.65, 341146.38), 31256), 4326) as b) as a
  • Please include the statement you are using to pass the point to ST_Transform()
    – kttii
    Jul 28, 2016 at 20:20
  • @kttii updated the questions with selectable example
    – JohnDoe
    Jul 28, 2016 at 20:39

3 Answers 3


It looks like PostGIS is performing some geographic/datum transformation because the output values aren't just the MGI Austria values unprojected into MGI latitude-longitude values (48.209213766 16.37385929).

I checked EPSG::1618 and EPSG::5891 but neither matched exactly. what you're getting from the mygeodata website. EPSG::1618, MGI to WGS 1984 (3) gave closer results. The EPSG::5891 transformation uses the NTv2 grid, AT_GIS.gsb.

It's possible the underlying PROJ.4 version doesn't have the NTv2 grid file (and the mygeodata doesn't either) or that the PROJ.4 definitions associated with MGI-based PCS haven't been updated to use one of the more recent transformations.

There's some information about it in the ST_Transform documentation.

  • When I perform the translation on the mygeodata - site it uses this paramters for Proj.4:, SRID=31256: +proj=tmerc +lat_0=0 +lon_0=16.33333333333333 +k=1 +x_0=0 +y_0=-5000000 +ellps=bessel +towgs84=577.326,90.129,463.919,5.137,1.474,5.297,2.4232 +units=m +no_defs whereas PostGIS has stored "+proj=tmerc +lat_0=0 +lon_0=16.33333333333333 +k=1 +x_0=0 +y_0=-5000000 +datum=hermannskogel +units=m +no_defs " in column proj4text.
    – JohnDoe
    Jul 29, 2016 at 6:04
  • That's epsg::1618.
    – mkennedy
    Jul 29, 2016 at 6:07

You are using ST_Makepoint which is expecting Lat Long values. To convert your 31256 SRID point to 4326 SRID you need to use ST_Point, set the SRID with ST_SetSRID and then transform it with ST_Transform in PostGIS 2.2.2:

SELECT ST_y(a.b) , st_x(a.b)
    SELECT ST_Transform(ST_SetSRID(ST_Point(3011.65,341146.38),31256),4326) as b) as a

and the result is:

48.20871308466652 16.372654668537162

and my values for SRID 4326 and 31256 are:

    srid    auth_name   auth_srid   srtext  proj4text
    4326    EPSG    4326    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"]]    
+proj=longlat +datum=WGS84 +no_defs 
    31256   EPSG    31256   PROJCS["MGI / Austria GK East",GEOGCS["MGI",DATUM["Militar_Geographische_Institute",SPHEROID["Bessel 1841",6377397.155,299.1528128,AUTHORITY["EPSG","7004"]],TOWGS84[577.326,90.129,463.919,5.137,1.474,5.297,2.4232],AUTHORITY["EPSG","6312"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4312"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",16.33333333333333],PARAMETER["scale_factor",1],PARAMETER["false_easting",0],PARAMETER["false_northing",-5000000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AUTHORITY["EPSG","31256"]]   
+proj=tmerc +lat_0=0 +lon_0=16.33333333333333 +k=1 +x_0=0 +y_0=-5000000 +datum=hermannskogel +units=m +no_defs 
  • That's strange, your select seems to give the correct answer while mine doesn't. SELECT PostGIS_full_version(); gives "POSTGIS="2.2.2 r14797" GEOS="3.4.2-CAPI-1.8.2 r3921" PROJ="Rel. 4.8.0, 6 March 2012" GDAL="GDAL 1.10.1, released 2013/08/26" LIBXML="2.9.1" LIBJSON="0.11.99" (core procs from "2.2.1 r14555" need upgrade) RASTER (raster procs from "2.2.1 r14555" need upgrad (...)"
    – JohnDoe
    Jul 28, 2016 at 20:44
  • use ST_Point the way I am for now rather than ST_MakePoint
    – kttii
    Jul 28, 2016 at 20:47
  • Tried that, it delivers the same (~wrong) result
    – JohnDoe
    Jul 28, 2016 at 20:47
  • updated answer... ST_MakePoint() is expecting Lat/Long
    – kttii
    Jul 28, 2016 at 20:49
  • @JohnDoe Updated my select statement to use your values
    – kttii
    Jul 28, 2016 at 20:53

I had the same problem. What I did was:


DELETE FROM spatial_ref_sys WHERE auth_srid = 31256;

Then (According to http://spatialreference.org/ref/epsg/mgi-austria-gk-east/postgis/):

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 31256, 'EPSG', 31256, '+proj=tmerc +lat_0=0 +lon_0=16.33333333333333 +k=1 +x_0=0 +y_0=-5000000 +ellps=bessel +towgs84=577.326,90.129,463.919,5.137,1.474,5.297,2.4232 +units=m +no_defs ', 'PROJCS["MGI / Austria GK East",GEOGCS["MGI",DATUM["Militar_Geographische_Institute",SPHEROID["Bessel 1841",6377397.155,299.1528128,AUTHORITY["EPSG","7004"]],TOWGS84[577.326,90.129,463.919,5.137,1.474,5.297,2.4232],AUTHORITY["EPSG","6312"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4312"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",16.33333333333333],PARAMETER["scale_factor",1],PARAMETER["false_easting",0],PARAMETER["false_northing",-5000000],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AUTHORITY["EPSG","31256"]]');

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