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I am a beginner using QGIS 2.18.15. I am having some trouble to find the right coordinate reference system for wind speed data of Europe from the German Weather forecast service (DWD). (ftp://ftp-cdc.dwd.de/pub/CDC/grids_europe/monthly/wind/MIKLIP_DECREG/v002/)

The data is projected in a regular rotating grid with a virtual North Pole at 39.25 N, 162.00 W (rotated coordinates). When I add the raster layer to QGIS it tells me that there is no “pre stetted” CRS so it automatically uses the CRS EPSG: 4326, WGS 84. As a result the layer of Europe is now half on Africa half on the Atlantic Ocean. So I looked for a possible CRS online but could not find any.

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As the grid is rotating someone told me that the question “Manually transforming rotated lat/lon to regular lat/lon?” might solve my problem. But it does not. In this question we got two data sets. I just have one data set in a rotating grid and I don’t have the according regular coordinate system. Further on I would still need to know the CRS of the out-put coordinates which I could not find online.

Another user told me to have a look at the question "Transforming data from a rotated pole lat-lon grid into regular lat-lon coordinates in QGIS?". As I am a total beginner of Python too, I am lost with the presented code. Copying and modifying with my values did not work out. I even still don’t know which CRS I would be supposed to use.

As I am trying everything I also tried affine transformation but as I could not chose my data set as a layer it first did not work out ether. I guessed that’s because my data is a raster-layer and not a vector-layer. So I transformed my raster into a vector layer. That workef out but I recieved this warning.

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The data set seems to have no time dimension or vertical dimension. Now I stack with the spreadsheet. I don’t know what I have to fill in.

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Is this even a right approach to solve the problem?

PolyGeo
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K. Friday
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  • You are not the first one facing this: https://stackoverflow.com/questions/31549880/how-to-convert-a-rotated-netcdf-back-to-normal-lat-long, https://gis.stackexchange.com/questions/57756/reprojecting-raster-data-from-a-rotated-pole-grid, https://knowledge.safe.com/questions/43959/netcdf-rotated-coordinate-system-rlat-rlon.html, – Marco Jan 30 '18 at 12:50
  • @Marco Thanks for your comment. The answer of the first link you recommended me guides me to [link] (https://code.mpimet.mpg.de/boards/2/topics/102) And here they have data according to xfirst and yfirst and xinc and yinc. Where do i got those datas from? – K. Friday Jan 30 '18 at 13:15
  • The second link guided me to the question I allready mentiont in my question. the third link https://knowledge.safe.com/questions/43959/netcdf-rotated-coordinate-system-rlat-rlon.html is containing a code but it asspect that we have the south pole data. I only have the north pole data. How can I change the code for that I can use it with the noth pole? – K. Friday Jan 30 '18 at 13:21

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