1

This is a newb question and I hope you all will be patient. The answer should be simple (I hope.).

I obtain gif and shp files from flying a drone and processing the images with DroneDeploy. The 1ft contour map created in QGIS from these two layers is very accurate. I would like to create elevation profiles so downloaded the Terrain Profile plug-in. But I understand I have to use an interpolation tool first and so downloaded the Raster Interpolation plugin. That tool wants to save the interpolation to a "destination" layer. I have none to choose from; the drop-down box is blank. I have a raster (gif) and a shape layer (shp). How do I create a destination layer for the interpolation? And then, once I have the interpolation, will the Terrain Profile plug-in automatically use it?

  • 2
    are you sure it's GIF format? While you can import GIFs into QGIS, you can't do much with them. It's not really a suitable format for geoprocessing. I can confirm Profile tool doesn't work on GIFs. Can DroneDeploy create GeoTIFFs for your DEM? If so, that might be a better bet? – Steven Kay Aug 29 '16 at 20:13
  • Yes, it IS a GeoTIFF. Sorry. I thought the SHP file would be interpolated, but it wants to interpolate the GeoTIFF and that's what I can't get working. Running the elevation profile with no interpolation step produces a curve that appears to be the second derivative of elevation, that is, not the elevation, not even the slope, but the change of slope. The data seems to be there. So close! – erkq Aug 29 '16 at 20:31
  • 1
    Could you add a screen shot of the interpolation plugin your using. I'm looking at mine and there is no box asking for a destination layer. The tool creates a new layer so shouldn't ask for another one. Also what is your GeoTiff of? Theres no need to interpolate a raster as it is already one. Only thing I can think off is you need to extract points from the contours for the interpolation to run which will give you a DEM product – Knightshound Aug 30 '16 at 7:35
  • I see no option to post a jpg. Is that a limitation because of my "newb" status on this forum? I know other forums don't allow that until the postcount gets higher. No option to make a new layer. But I thought it made sense for it to create a new layer. My GeoTIFF is of a 46 acre project site. It imports and presents as a raster but generates the aforementioned very strange elevation cross-sections. – erkq Aug 30 '16 at 18:18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.