This is really interesting. I found a PDF with some neat details and imagery describing the thinking that goes into Auto GCAS:

http://www.sfte2013.com/files/78993619.pdf

I don't know if it's just coincidental, but a lot of the examples seem to be concerned with keeping jets from flying into mountains, as opposed to flying into level ground, which was the first thing that came into mind when I saw "Ground Collision."