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I want to import DXF/DWG files in QGIS, therefore I use the import function. The problem is, that I have to know the crs of the CAD file. Is there any way to get the crs in QGIS, because I have no access to a CAD programm.

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  • I dont think (I may be wrong) that the CRS is included in a DXF or DWG (maybe if it's from AutocadMap a DWG could have a CRS). my workflow is to load the CAD doc in QGIS (empty .qgs with ''no projection'' set as CRS) and guess the right CRS by looking at the coordinate (but in my area it's usually one of the three CRS used by topographer or the dreaded draw in a random place (mostly used by architect)).
    – J.R
    Sep 12 '19 at 13:33
  • Where is the area mapped? Is it in feet or meters? Use the search box on www.spatialrefernce.org to narrow it down, e.g. Canada gives around 30 results.
    – vinh
    Sep 12 '19 at 14:48
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If QGIS does not read it than you'll have to play the CRS dwg guessing game:

  1. Add control layer in Q that you know the CRS
  2. Add in the dwg or dxf file
  3. In Q change the project>properties>CRS to any possible CRS the dwg might be in (this is assuming you have knowledge of the geography of the dwg/dxf file). If the data aligns with the control layer then you've finished the game and figured out the CRS it was in!
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    +1 for "The CRS Guessing Game." Someone needs to make a graphic for a fictitious game show, and start selling tshirts.
    – csk
    Sep 12 '19 at 19:15
  • what nightmare to "play" this
    – Louis
    Jul 8 at 14:45

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