A well produced video showing some Lidar examples. http://www.youtube.com/watch?v=tcdIHx9O5P8&hd=1 This unit has been used on RC aircraft a few times with good results. http://products.rieglusa.com/item/airborne-scanners/-580-laser-scanner-with-online-waveform-processing/vq-580?
The video is pretty cool. You should find out when they are going to scan a local mountain so we can go stand on it and be immortalized in their digital map. But the second link shows the unit weighs 13 Kg. You're gonna need a bigger tricopter.
