[Liblas-devel] ECEF?

[Howard Butler]

I just tested with the head, and the GeoTIFF keys have the flattening and axis from the WKT, but it seems the WKT is getting tossed out in some way.

Frank?

Howard


On Mar 7, 2011, at 6:52 PM, Ben Discoe wrote:

> OK, i went ahead and rebuilt liblas with full gdal/geotiff support, and wrote LAS files with the ECEF WKT that was discussed.
> 
> However, lasinfo output doesn't show the actual WKT.  You can try it yourself on the attached file (ecef_1point.las).
> 
> I used this when i wrote file with liblas:
> 
>     liblas::SpatialReference srs;
>     srs.SetWKT("GEOCCS[\"WGS 84 (geocentric)\",\n\
>    DATUM[\"World Geodetic System 1984\",\n\
>        SPHEROID[\"WGS 84\",6378137.0,298.257223563,\n\
>            AUTHORITY[\"EPSG\",\"7030\"]],\n\
>        AUTHORITY[\"EPSG\",\"6326\"]],\n\
>    PRIMEM[\"Greenwich\",0.0,\n\
>        AUTHORITY[\"EPSG\",\"8901\"]],\n\
>    UNIT[\"m\",1.0],\n\
>    AXIS[\"Geocentric X\",OTHER],\n\
>    AXIS[\"Geocentric Y\",EAST],\n\
>    AXIS[\"Geocentric Z\",NORTH],\n\
>    AUTHORITY[\"EPSG\",\"4328\"]]");
>     header->SetSRS(srs);
> 
> However, lasinfo reports this:
> 
>   Spatial Reference:
> LOCAL_CS["unnamed",
>     UNIT["metre",1,
>         AUTHORITY["EPSG","9001"]]]
> 
> It then shows a whole bunch of wrong and/or irrelevant info:
> 
> Geotiff_Information:
>    Version: 1
>    Key_Revision: 1.0
>    Tagged_Information:
>       End_Of_Tags.
>    Keyed_Information:
>       GTRasterTypeGeoKey (Short,1): RasterPixelIsArea
>       GeographicTypeGeoKey (Short,1): User-Defined
>       GeogGeodeticDatumGeoKey (Short,1): User-Defined
>       GeogAngularUnitsGeoKey (Short,1): Angular_Degree
>       GeogEllipsoidGeoKey (Short,1): User-Defined
>       GeogSemiMajorAxisGeoKey (Double,1): 6378137
>       GeogInvFlatteningGeoKey (Double,1): 298.257223563
>       ProjLinearUnitsGeoKey (Short,1): Linear_Meter
>       End_Of_Keys.
> 
> It seems that LAS/liblas just doesn't support geocentric CRS.  Any ideas?
> 
> Thanks,
> Ben
> 
> <ecef_1point.las>_______________________________________________
> Liblas-devel mailing list
> Liblas-devel at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/liblas-devel