2019-08-14
QGIS: latitude coordinates are reversed; map upside down
stackoverflow
Question

I have been using QGIS to display a map of the long term precipitation average of the Netherlands. However, when QGIS opens the data, the map is shown upside down

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I noticed that the coordinates are displayed from 0 - 266 (lon) and -315 - 0 (lat). I figured that the latitude is projected upside down

enter image description here

In stead of -315 - 0 it should be 0 - 315 and the map should look fine. But I can't figure out how to inverse this value. The file is a NetCdf file. I openend the XML metadata QGIS made for me with EmEditor, but it did show the right coordinates (in lat/lon), So I think it has something to do with the way QGIS sets up the map or the way it converses the lat/lon to meters. Anybody who encountered the same problem as me? Thank you in advance!

Answer
1

Thanks to Micha (see the comments):

I was told to solve the problem using GDAL (Geospatial Data Abstraction Library), a method to look into and translate/process metadata. This was quitte hard to understand, while I am relatively new in programming and using powerfull 'languages' like GDAL. To enter GDAL codes I used the OSGeo4W Shell, which comes with QGIS. The command that I used to flip my map was:

gdal_translate -of netCDF -co WRITE_BOTTOMUP=NO my netcdf.nc output.nc

(see also this short GDAL/netCDF introduction).

QGIS: latitude coordinates are reversed; map upside down
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