Remote aerial surveys (photogrammetry) using Unmanned Aerial Vehicles (UAVs)
Aerial photography is an efficient tool of the topographic mapping almost since the photography has been invented.
The photogrammetry is the science of obtaining information from photographs, especially for recovering the exact positions of surface objects, their shape and dimensions. This makes possible obtaining 2D & 3D models of the objects. Aerial photography is used, from the middle of XX century, in geological studies for the structure analysis and interpretation of different geological objects.
The main negative feature of these methods was their high cost related to the using of aircrafts. This obstacle is not so critical now because of the development of Unmanned Aerial Vehicles (UAVs) and corresponding software, that is why the obtaining of coordinate dimensioned photographs and digital elevation models (DEM) becomes more accessible. The accuracy of topographic control and survey resolution was increasing during last several years. It is now reaches the precision of ground measurements.
UAVs photography advantages compared with satellite imagery and ground topographic surveys: