I generated this shaded image of Pendle Hill using GDAL and the Elevation dataset on AWS.
First I found the bounding box of the area using this tool.
Then I used GDAL to stitch together a Geotiff of the elevation data from S3.
GDAL v2 wasn’t available through Homebrew so I used a Docker container instead.
Watch out for the gotcha that the coordinate bounds (specified as
projwin) are expected in a different order to the bounding box above.
The elevation.xml is a GDAL WMS that specifies how to get the tiles from S3, you can download it here.
docker run -v $(pwd):/gdal -w /gdal geographica/gdal2 \ gdal_translate \ -of GTiff \ -projwin -2.41081 53.911186 -2.185871 53.814308 \ -projwin_srs EPSG:4326 \ elevation.xml pendle.tif
Then I used the GDAL
hillshade command to generate the shaded image. The
-z flag is used to exaggerate the terrain slightly and
-az is used to specify the location of the light source.
docker run -v $(pwd):/gdal -w /gdal geographica/gdal2 \ gdaldem hillshade \ -az 45 -z 8 -compute_edges \ pendle.tif pendle-shaded.tif