Question

CoordinateExtractor not giving correct values for GDA94 after using Reprojector

  • 22 January 2019
  • 3 replies
  • 10 views
andrewandkym
Rank

Hello FME gurus

 

I want to reproject some GDA data to MGA and then reproject back to GDA and extract some coordinates but am getting weird values for the GDA coordinates. I’m confident the problem is with the CoordinateExtractor tool when used in combination with the Reprojector tool.

 

To test it, I have set up this workbench where I started with a SHP file in GDA94 projection then:

  • Exported the coordinates
  • Reprojected to GDA94 MGA56
  • Exported the coordinates
  • Reprojected to GDA94
  • Exported the coordinates
  • Reprojected to GDA94 MGA56
  • Exported the coordinates

 

Workbench looks like this:

 

 

 

Below is the results. Yellow is the exported data in GDA94 and blue is the exported data in GDA94 MGA56. The blues match, but the yellows don’t, although they should.

 

Any ideas why the coordinate extractor is giving me the wrong coordinates?

 

Thanks

 

Kym

 

3 replies

jovitaatsafe
Rank
Userlevel 1
Badge +11

Hi @andrewandkym,

Thanks for sharing your question! Would it be possible to share your workspace and sample data?

andrewandkym
Rank

Hi @JovitaAtSafe

Please find files below:

I am using FME 2017.1.0.0

files.zip

 

jovitaatsafe
Rank
Userlevel 1
Badge +11

Hi @andrewandkym,

Thanks for sharing your data! It looks like the source GDA94 coordinate system is different from the one specified in the Reprojector. The source shapefile has a coordinate system that is specified in degrees called LL-GDA94_0, while the Reprojected coordinate system is set to GDA94 Geoscience Lambert (EPSG 3112) which is in meters. This then accounts for the reprojected points being in the correct location but with very different X and Y coordinates.

 

Try changing Reprojector_2 to LL-GDA94 and you should get the same coordinates as the source input when reprojecting back to GDA94.

 

Reply


Community Stats

28,661
Posts
109,318
Replies
36,527
Members
Terms & ConditionsCookie settings
A product of
Safe Software respectfully acknowledges that we live, learn and work on the traditional and unceded territories of the Kwantlen, Katzie, and Semiahmoo First Nations.