[GIS] Importing .csv to QGIS gives CRS undefined (but not always)

coordinate systemcsvimportmacqgis

I wonder why some .csv files when imported (with long and lat) can not set a proper CRS system and other do (CRS undefined). For example:

  1. If I export my data in csv with Microsoft Excel it does not set the CRS and can not be fixed.
  2. when I export with Google Sheets it does work.

What is the problem in this case? I am trying to export data with pandas python but can not figure out this problem? I am using QGIS, 2.12.1-Lyon, on MAC.

Best Answer

CSV files do not contain any CRS information, just coordinates.

In QGIS, take a look at Settings -> Options -> CRS tab. Under CRS for new Layers you can choose Prompt for CRS. It might be set to a default CRS of WGS84 using degrees, and if the coordinates exceed +/-180/90, the CRS will be set to undefined.

Apart from that, QGIS on MAC has some problems with CR-LF in CSV files, see QGIS won't read table columns in CSV import on Mac OS and https://stackoverflow.com/questions/22052168/excel-saves-tab-delimited-files-without-newline-unix-mac-os-x

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