Unmanned Aerial Vehicles (Drones)

Octocopters are primarily used for selected single shot imagery, sequential imagery of business and residential buildings and particularly demanding video imagery. These UAVs are semi-autonomous, stable in flight, and can be navigated with GPS in particularly narrow spaces.  Their capacity for vertical take-off and landing allows them to be manoeuvred in inner city and other limited spaces. The cameras and other sensory systems can be operated independent of the aerial vehicle’s controls.

Fixed wing UAVs are more suitable for a full surface survey where there is sufficient space for take-off and landing. These UAVs are capable of a longer flight time, thus have a greater range which allows them to survey a larger surface area.

UAVs can be put to a wide range of uses and are quite versatile. The efficient use of UAVs is chiefly limited by their operating parameters. In comparison with conventional aircraft and helicopters these parameters include limits on flight range and project area size; and a reduced range of available sensors.  In addition the optimal weather conditions for flying UAVs are restricted, as is the range of altitude at which they can fly; the latter being a determinant of ground resolution requirements.

In concrete terms UAVs are used for construction site monitoring, the evaluation of archaeological finds, cadaster for outdoor facilities or agricultural field data. In difficult to access areas drones can supplement or replace other conventional survey systems.

Orthophotos can also be generated from UAV imagery, used in mapping and as background imagery in GIS systems, as in the above example. Finally rectified imagery can be used to generate 3D terrain models eg for the preparation and monitoring of major events.