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Ticket #1987 (new defect)

Opened 8 months ago

Last modified 8 months ago

EPSG:28992 - Lacking datum parameters for Amersfoort

Reported by:	johantenbreteler	Assigned to:	warmerdam
Priority:	normal	Milestone:
Component:	OGR_SRS	Version:	svn-trunk
Severity:	normal	Keywords:	datum shift
Cc:	mloskot

Description

When I try to do a conversion from shp file to a kml format the result in google earth is not exactly the position which the converted info should be have. It seems that there a kind of offset. I try to convert from EPSG:28992 to WGS84. I found a work around for this problem , but I wondering that it works so. failing method

ogr2ogr -f KML -t_srs WGS84 -s_srs EPGS:28992 <file>.kml <file>.shp

work around

ogr2ogr -f KML -t_srs WGS84 -s_srs "+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.999908 +x_0=155000 +y_0=463000 +ellps=bessel +towgs84=565.237,50.0087,465.658,-0.406857,0.350733,-1.87035,4.0812 +units=m +no_defs <>" <file>.kml <file>.shp

So if not using the EPGS:28992 mnemonic gives a correct translation to WGS84. I don't known what the reason is that the work around works. I try the conversion with FwTools? pack 1.4.2 .

Change History

11/13/07 09:43:51 changed by warmerdam

keywords set to datum shift.
version changed from unspecified to svn-trunk.
component changed from default to OGR_SRS.
summary changed from Conversion error from shp files to kml format to EPSG:28992 - Lacking datum parameters for Amersfoort.

The default expansion of EPSG:28992 is as follows which lacks towgs84 parameters. The issue is (presumably) that EPSG offers conflicting transformations and so OGR ignores them all as expected.

PROJCS["Amersfoort / RD New",
    GEOGCS["Amersfoort",
        DATUM["Amersfoort",
            SPHEROID["Bessel 1841",6377397.155,299.1528128,
                AUTHORITY["EPSG","7004"]],
            AUTHORITY["EPSG","6289"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.01745329251994328,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4289"]],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    PROJECTION["Oblique_Stereographic"],
    PARAMETER["latitude_of_origin",52.15616055555555],
    PARAMETER["central_meridian",5.38763888888889],
    PARAMETER["scale_factor",0.9999079],
    PARAMETER["false_easting",155000],
    PARAMETER["false_northing",463000],
    AUTHORITY["EPSG","28992"]]

I'm going to leave this open as a reminder to review the datum shift selection rules when OGRSpatialReference expands EPSG definitions.

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