GDAL Hillshading
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.
-2.41081,53.814308,-2.185871,53.911186
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