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It seemed to be easy but make big problems, perhaps it is a beginner mistake. Anyway I have to ask you: I need to lay two shapefiles over each other to make a spatial query. The coordinate systems of both shapes are unknown. But I now the one shape was projected in ETRS-1989_LAEA originally; it is a download from here (Berlin). The other shape file was projected in DHDN_Soldner_Berlin.

Now I tried to project the first shapefile to its original coordinate system with the tool “define project” and did the same with the second one. Loading both shape files with different coordinate systems to a data frame the shapefiles are not lying over each other. So I tried to import both to a feature dataset in the File geodatabase. The feature dataset got the coordinate system from the first shape so ETRS-1989_LAEA. Then I import both shapefiles to the feature dataset in the File geodatabase. But this is also not working; the shapes are not laying over each other.

But did I wrong, how can I get both shapes which having different coordinate systems over each other? On the fly is also not working, when I project the coordinate systems from one shape.

Projecting the first shape in the coordinate system from the second shape with the tool “project” is working. But load both shapes having DHDN_Soldner_Berlin as coordinate system to ArcMap 10.2 is again not working.

I read in the forum about the issue but I cannot find my mistake.

Here is the extent from the first shape

enter image description here

Here is the extent from the second shape

enter image description here

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    Two shapefiles covering the same area with correct projections defined on them should overlap no matter where you store them. Is it possible that you have got the coordinate systems confused somehow? Good that you use Define projection and not Project, since the latter actually changes the coordinates stored in your shapefile (and you don't need that for them to overlap). – Martin Sep 17 '14 at 12:54
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    At the moment I’m also thinking that the second shape file must have another coordinate system before. The person who gave me the shape is still saying that it had DHDN_Soldner_Berlin originally. I really don’t know what to do now. Doing the same with other shape files (“define projection”) and put them to a data frame works. – Nora Sep 17 '14 at 13:09
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    There's no easy way of dealing with this, although it is a quite common issue. Add a layer that you know is of the same area and in the appropriate coordinate system to a new mxd. Delete the .prj-file of the shapefile which is not aligning with the rest, and add it too to the mxd. In the Dataframe properties Coordinate systems dialog box, change the coordinate system of the data frame to other systems one by one and see when your data overlap. You need to first think about which coordinate systems it could possibly be in, and then try them all. Hopefully one will make your data overlap. – Martin Sep 17 '14 at 13:15
  • If you overlay the two shapefiles: How many meters differ the shapefiles from each other? – Jens Sep 17 '14 at 13:33
  • Okay, after a big search I found a hint for the original coordinate system. The shapes are laying over each other now! I just thought that I did something wrong therefore I asked … Thank for the answers – Nora Sep 18 '14 at 8:21
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Since you work with data for Berlin, I do not believe that the second shapefile is DHDN_Soldner_Berlin. I assume the right coordinate system is EPSG 3045 - ETRS89/UTM zone 33 (N-E).

Try to use Define Projection Tool (not Project Tool!) and overwrite the coordinate system information with is EPSG 3045 - ETRS89/UTM zone 33 (N-E) (the name my differs in ArcGIS).

Reasons why I assume EPSG 3045 - ETRS89/UTM zone 33 (N-E) is the right system:

Typical coordinates (DHDN_Soldner_Berlin) for the area of Berlin should fall in this range (about):

  • min x: 3,000
  • max x: 49,000
  • min y: 2,000
  • max y: 38,000

The coordinates of your second shapefile did not fit to this extend. So your second shapefile is not DHDN_Soldner_Berlin.

But what is the right coordinate system?

Berlin is surrounded by Brandenburg. In Brandenburg UTM 33 is used. The extent of Berlin in UTM 33 is about:

  • min x: 370,000 (or 3,370,000 or 33,370,000
  • max x: 416,000 (or 3,416,000 or 33,416,000)
  • min y: 5,800,000
  • max y: 5,837,000

Your coordinates fall in this range.

There are 3 different UTM 33 systems in use which only differs in false easting resulting in x coordinates with 6, 7 or 8 digits.

For your data EPSG 3045 - ETRS89/UTM zone 33 (N-E) which uses a false easting of 500,000 fits best (6 digits x-coordinate).

  • Okay, after a big search I found a hint for the original coordinate system in the net. The shapes are laying over each other now! I just thought that I did something wrong therefore I asked … Thank for the answers! The right one is EPSG: 25833. – Nora Sep 18 '14 at 8:24

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