Hallo,
I try to transform Points from Gauss-Krueger-System (EPSG 31466) to ETRS89 Zone 32N (EPSG 25832) with ManagedProj4Projection.
The results have a shift in both directions between 50 up to 200 meters.
My reference is a offical WebSite from an GIS-Departement in Wuppertal. According their results, the Transforming of
Gauss-Krueger-Coordinate (X: 2583800, Y: 5682600) must be
ETRS89 32N -Coordinate (X: 32374454, Y: 5681620)
But the ManagedProj4ProjectionResult is (X: 32374513, Y: 5681763)
InternalParameterstring:"+proj=tmerc +lat_0=0 +lon_0=6 +k=1 +x_0=2500000 +y_0=0 +ellps=bessel +datum=potsdam +units=m +no_defs"
ExternalParameterString: "+proj=utm +zone=32 +ellps=GRS80 +units=m +no_defs"
Missed I something, any help is welcome
Torsten
Projection Gauss-Krueger to ETRS89 32N
Hi Torsten,
As you known, our reprojection based on Proj4 , I Google a online service which is also based on proj4 : cs2cs.mygeodata.eu/
And the result like this:
Input coordinate system / projection: 31466
Output coordinate system / projection: 25832
Input coordinate pairs: 2583800, 5682600
Output - transformed pairs: 374513.122553;5681762.52933
It looks the result is the same as ours. So I think that’s should be the result of Proj4.
For make sure that, maybe you need find another reprojection library or GIS product for compare. We will did more research about it also.
Regards,
Don
Hi Don,
Thank you for your answer. I have checked some Websites with services for coordinate-transformation. The results are different, but in most cases they are nearly to my reference-Coordinate.
Please check word-coordinate-converter. For Input (EPSG: 31466; X:2583800,Y:5682600) the result is there (EPSG: 25832, X:32374456.38, Y:5681615.95)
Another question (I don’t want create a new topic):
Some of my costumers complains, that their ECW-Files are not display correctly. Not correctly means: The parameters in their ECW-Files for the Coordinatesystem are ignored. I try to find the problem and I can only fix it with the creation of a wordfile (eww). I can’t remember that this was necessary in MapSuite (before version 7).
The question: Ecw-Files now MUST have an eww file?
Regards
Torsten
Hi Torsten,
We did more investigations and the results are similar with
Don’s. like Don mentioned, our projection system is based on Proj4 and there are
some authority online service using Proj4:
tasks.arcgisonline.com/ArcGI…er/project
Both of the projected results are the same with ours. But we
also noticed some online test result is similar with yours like geoconverter.hsr.ch/ and twcc.free.fr/. I am not sure what’s project library
they are based on but as I know the Proj4 should be one of the most famous
projecting libraries.
As for the other question about Ecw position. I can see the
behavior by comparing the boundingbox of the ecw when I try to load a ECW file
with eww file and without the file. The reason is when there is no eww file, it
will read world file information from the native Ecw file and if there is a eww
file, it will read the world file information from this file. Based on this
point, we can’t make sure the two part of information are the same. Currently,
I guess owing the eww file would be more accurate in your case if necessary.
Any questions please feel free to let us know.
Regards,
Johnny
Hi Torsten,
Sorry for the waiting.
We did more investigations and the results are similar with Don’s. like Don mentioned, our projection system is based on Proj4. There are some authority online service using Proj4:
tasks.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer/project
cs2cs.mygeodata.eu/
Both of the projected results are the same with ours. But we also noticed some online test result is similar with yours like geoconverter.hsr.ch/ and twcc.free.fr/. I am not sure what’s project library they are based on but as I know the Proj4 should be one of the most famous projecting libraries.
As for the other question about Ecw position. I can see the behavior by comparing the boundingbox of the ecw when I try to load a ECW file with eww file and without the file. The reason is when there is no eww file, it will read world file information from the native Ecw file and if there is a eww file, it will read the world file information from this file. Based on this point, we can’t make sure the two part of information are the same. Currently, I guess owing the eww file would be more accurate in your case if necessary.
Any questions please feel free to let us know.
Regards,
Johnny