South America Datum 1969 (EPSG:4618) has incorrect transformation parameters to WGS84

[ccnbox]

South America Datum 1969 (SAD69) (EPSG:4618) has the following transformation parameters to WGS84: X-axis translation: -57 m Y-axis translation: 1 m Z-axis translation: -41 m

But when converting a file in South America Datum 1969 from/to WGS84 using the EPSG:4618 code these parameters are ignored. Both for gdalwarp and ogr2ogr.

Reproducing the problem: Convert the attached file (file_WGS84LL_EPSG4326.shp) from WGS84 to SAD69 using the EPSG code and back using the explicit parameters (with proj4):

• ogr2ogr -s_srs EPSG:4326 -t_srs EPSG:4618 file_SAD69LL_EPSG4618.shp file_WGS84LL_EPSG4326.shp
• ogr2ogr -s_srs EPSG:4326 -t_srs "+proj=longlat +a=6378160.0 +b=6356774.719 +towgs84=-57.0,1.0,-41.0,0,0,0,0 +no_defs" newfile_WGS84LL_EPSG4326.shp file_SAD69LL_EPSG4618.shp

The files file_WGS84LL_EPSG4326.shp and newfile_WGS84LL_EPSG4326.shp will be different. References:

• ​http://www.eye4software.com/resources/datum/4618/
• ​http://www.epsg-registry.org/, with code 1864 (SAD69 to WGS84 (1))

Note: Information in: ​http://spatialreference.org/ref/epsg/4618/, also has To WGS84 missing.

[Even Rouault]

Is now fixed in GDAL trunk by the EPSG database update.

Now we have :

PROJ.4 rendering of [EPSG:4618] = +proj=longlat +ellps=aust_SA +towgs84=-57,1,-41,0,0,0,0 +no_defs