Question

reprojection error too big

  • 9 October 2015
  • 2 replies
  • 3 views
J
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Hello,

 

would anyone have a solution for this problem?

 

I have the vector street data in WGS84 (EPSG:4326) and transform them to EPSG:28404. The transformation is done with error of 11m, which is way too much. I compared the transformed coordimnates with MapInfo transformation, also with some www online transformers and see that this if FME who has error in the calculation.

 

So I tried the CSmap transformer, played with Z coordinate, but there are no meaningful results. I am still having an offset of 11m, +/- constant accross all the country. Just FYI, the data sit around 48N, 17E.

 

 

 

2 replies

david_r
Rank
Userlevel 4
Hi

 

 

If you suspect that it is an error in FME, consider trying the ESRIReprojector transformer. It will use the ESRI ArcGIS libraries for the reprojection rather than the FME ones. Note that you will need an ArcGIS license for this to work.

 

 

David
J
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Hi David,

 

meanwhile I found out that there are multiple definitions of EPSG:28404. The FME's transformer rigidly uses the parameters deltaX=28 deltaY=-130 deltaZ=-95. However, this is a valid setup only for Russia. For other countries, the deltas are different. So I looked up those I needed and created my custom transformer which gives satisfactory results.

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