Hi,
I'm getting shape files from clients in Asia in Timbalai datum using custom RSO projections. In my code, I'm using the ConvertPrjtoProj4 method to get the transformation parameters. But when the prj file is read and I assign it to the InternalProjectionParameters string, it just reads string.empty.
Attached is an example file. The .prj looks okay to me. Can you please see why the parameters are not being passed?
Thanks,
Damian
TimbaliConversion.zip (2.06 KB)
Hi Damian,
I think the prj string is wrong, please see the page edndoc.esri.com/arcobjects/9…htm
As you can see the Esri id is 29873, then I use the ManagedProj4Projection.ConvertEpsgToPrj(29873) and get the following string:
PROJCS[“Timbalai_1948_RSO_Borneo_m”,
GEOGCS[“GCS_Timbalai 1948”,
DATUM[“D_Timbalai_1948”,
SPHEROID[“Everest_1830_1967_Definition”,6377298.556,300.8017]],
PRIMEM[“Greenwich”,0],
UNIT[“Degree”,0.017453292519943295]],
PROJECTION[“Hotine_Oblique_Mercator_Azimuth_Natural_Origin”],
PARAMETER[“latitude_of_center”,4],
PARAMETER[“longitude_of_center”,115],
PARAMETER[“azimuth”,53.3158204722222],
PARAMETER[“scale_factor”,0.99984],
PARAMETER[“false_easting”,590476.87],
PARAMETER[“false_northing”,442857.65],
UNIT[“Meter”,1]]
So please replace the string in the prj file with the correct string.
Hope it helps,
Edgar
Hi Edgar,
Yes, editing the prj allowed me to load the shape fine.
It seems though that the issue of returning a null projection string may be with the naming of the projection. "Rectified_Skew_Orthomorphic_Natural_Origin" is a valid projection type in many GIS packages, but if I leave this text in the Projection field of the .prj, MapSuite just ignores it.
According to some of the literature I've seen on the internet, these two descriptions are synonymous, so maybe this description should be added to the library so we can avoid returning null projection strings and forcing users to edit prj files? Maybe it's not that simple?
Regards,
Damian
Damian,
We are sorry that we cannot add this to the library because we are using the third part projection logic, we are not sure if there are some problems after we make the changes, So sorry for the inconvenience.
Best Regards,
Edgar