We used to survey this big waste management site twice a year with our long range 3D scanner (Reigl 420i at the beginning, then our Riegl 620).
The goal was to monitor settlements and to deliver accurate volumes.
An overview of the 3D mesh derived for our Riegl measurement
One day, our client asked us to fill up our maps with an orthophoto with a resolution of 5cm : we already had the DEM, we just lacked the photos. So we spent a day on the field, positionning big targets with our GPS, then we hired a little plane for an hour and we photographed the site with or Canon EOS I Ds Mark II (17 millions pixels).
Overall, that was easy to do, and a very cheap solution !
Click to enlarge