I'm running some statistical comparisons between several DEMs (SRTM, ASTER, ALOS...) through GRASS-GIS and Python. Dealing with millions of cells is not very practical, so I thought I could compare elevation values from random points. How many points should I use? 5000? 10000?
Of course, the more, the better. But then I went searching for any literature on the subject and couldn't find anything with a good answer.
Can someone point me a good article on this?