While researching for a new painting assignment I came across this site
for satellite maps:
http://landsat.org/landsat_gallery/EP105R11D091001.html
I had my students view them and use them as the basis for a non-objective
painting, noting the "color-coding" and textures. They made sketches of
portions they especially liked, with a variety of shapes and textures, and
are using the sketches to create a composition. They will later create
their own color coding to denote particular features.
The maps are really gorgeous, and I think the paintings will come out
equally so.