Unmanned aerial photogrammetric survey
The unmanned aerial photogrammetric survey is the use of unmanned aerial vehicles (UAVs) to take photos for use in photogrammetry, the science of making measurements from photographs. Instruments manufactured for UAVs could be mounted on unmanned flying platforms of various sizes and types, such as octocopters.
Source: Wikipedia — Unmanned aerial photogrammetric survey (CC BY-SA 4.0)