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EDIT: it is seeming like some of the time my last method will lead to a correct projection, some of the time it will not. Unsure what's happening there but at least trial and error will get me through what I'm doing now. Any suggestions for a more robust method would be appreciated.

apologies if this has been answered somewhere, but I've not found a solution I could get working.

I have a DEM file that I need to change the projection of, and then export for use in another program (accepts gdal). I am using QGIS. I can import it to QGIS and change the projection no problem, but cannot figure out how to export the result for rasters (fine for vectors).

I have tried using the clipper to save a copy, however this changes the projection to WGS84, defeating the purpose. I have set the project to my projection of choice AGD66, and in Settings/Options have set all options to this projection. The clipper always converts to EPSG:4326 - WGS 84. I have tried both with and without on the fly reprojections.

I have tried to use the GRASS plugin and use r.out.gdal.gtiff and r.out.gdal, however output files are all blank.

Through the Sextante toolbox I have tried GDAL Conversion/Translate however this too puts everything in EPSG:4326 - WGS 84. The option "Override the projection for the output file" with AGD66 selected led to the error


An error has occured while executing Python code:

Traceback (most recent call last): File "C:/Users/.../.qgis//python/plugins\sextante\gui\CrsSelectionDialog.py", line 47, in okPressed self.authid = self.selector.selectedAuthId() AttributeError: 'QgsProjectionSelector' object has no attribute 'selectedAuthId'

Python version: 2.7.2 (default, Jun 12 2011, 15:08:59) [MSC v.1500 32 bit (Intel)]

QGIS version: 1.8.0-Lisboa Lisboa, f440b60

Python path: ['C:/Users/.../.qgis//python/plugins\sextante', 'C:/PROGRA~2/Quantum GIS Lisboa/apps/qgis/./python', 'C:/Users/.../.qgis//python', 'C:/Users/.../.qgis//python/plugins', 'C:/PROGRA~2/Quantum GIS Lisboa/apps/qgis/./python/plugins', 'C:\PROGRA~2\Quantum GIS Lisboa\bin\python27.zip', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\DLLs', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\plat-win', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\lib-tk', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\qgis\bin', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\PIL', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\win32', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\win32\lib', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\Pythonwin', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\Python27\lib\site-packages\wx-2.8-msw-unicode', 'C:\PROGRA~2\Quantum GIS Lisboa\apps\qgis\python\plugins\fTools\tools']


I thought I had a solution using Raster/Converstion/Translate (convert format) as this runs and lets me set the Target SRS, however the output is still EPSG:4326 - WGS 84. I do get the following error


Warning 6: A dataset opened by GDALOpenShared should have the same filename (C:\Users...\demh\w001001x.adf) and description (C:...\demh)


Any suggestions for how I can get raster data OUT of QGIS would be very much appreciated. Or - if you can't get data out of QGIS, can you suggest an alternative free GIS system that works nicely with projections? I have tried SAGA, however have not had much luck getting reprojections to work properly.

Thanks

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In QGIS, Raster -> projections -> warp calling GDAL's gdalwarp utility is the method to change the CRS of a raster file.

This is an external command, so it does not look at the project or layer CRS you might have set in QGIS.

Select the right CRS for source, and the desired for target CRS, abd give the output a different filename. You can add the result to the canvas, and check the extent in the layers properties, metadata tab. It should be different from the originals extent

  • Thankyou very much for the help Andre, much appreciated. This looks to also have solved another problem I had with area calculations going wrong. Thanks again – Esme_ Jul 19 '13 at 5:59
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Since QGIS 2.0 will be out soon, I think it's necessary to mention that in 2.0 raster layers also have a "Save as ..." option - just like vector layers - which will make things much easier.

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