Testing the resolving power of a telescope?

Hi ppl

I was just wandering if it is possible to do a ground-based test of
the resolving power of a telescope. With ground-based I mean you look
at a target on earth, to exclude seeiing. I tought on something like
http://www.efg2.com/Lab/ImageProcess...s/Image133.gif
placed some 20-30 meters away or so.
Would this work for a telescope test?

Thanks for your help!
Pieter