@Setanta,
neat. LIDAR is a neat technique that reads nd analyzes the differences in slopes only. It doesn't read elevations . So the maps it produces uses a algorithm called "Slope Shading", in which any slope of the bare ground will be darkened depending upon how steep it is. If they come across a ruin of a series of walls (like they did), the walls will show up as black and any level areas will show up as white and tones of grey.
Those LIDAR shots are really neat. They must be a newer generation gizmo. Cause I see that the resolution is much smaller than what Im was used to.