Creating a DEM from vector data
This article is part of the old QGIS tutorial, which is no longer maintained. The article will soon be edited to provide a standalone exercise.
- Add the vector layer goesrtm.shp. This is a point vector generated from SRTM digital elevation model with a 90m interval.
- Zoom in and click with the “Identify Features” tool on a point and identify the attributes.
- Open the GRASS toolbox with LOCATION: goegk, MAPSET: user1
- Import the vector layer goesrtm.shp with the v.in.ogr of the GRASS tools module list.
- We now want to interpolate the points to a surface with the same raster resolution like the multispectral LANDSAT7 ETM+ Bands: 30 m. Open the GRASS shell . Type in g.region. rast=etm10 Enter
- Control the region settings with of the GRASS tools.
- Create a new surface with the Inverse Distance Weighted (IDW) Interpolation algorithm using v.surf.idw from the modules list: filename: goesrtm, attribute field: Z, Number of interpolation points: 24, Name of the raster file: goedem.
- Open the GRASS module r.out.gdal:
Input layer: goedem
GIS format: GTiff
Save output as goedem in your /geodata folder
- Set the properties for the new layer goedem:
- Render as Single gray band
- For color map choose Pseudocolor from the dropdown-list.
- Mark Invert color map
- Change settings for standard deviation