Recently, I have been working on algorithms which needs elevation data as well as Land Cover data, with world coverage. Google has an excellent elevation API however free usage comes with a limit.
While searching, I came across a dataset in geotiff format for landcover as well as a processed version of world elevation. Elevation data comes in various resolution (250m,500m,1km), landcover is 500m .
So how do we read it ? In python its quite easy to use osgo/gdal library and read all bands. Geotiff is a rster file and values can be packed in every band (which is basically a 2d array).