Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
The Conyca Geodrome is a 1.5m fixed-wingdrone that specializes in topography and photogrammetric applications. It has all the legal requirements to operate in Spain. The system has totally autonomous take-off and landing operations, can present 3Dterrain models with 4 cm resolution accuracy at 100 m height, and can take orthophotos. Although this system has been orientated to topography, there are surveillance and precision agriculture versions than can use infrared and hyperspectral cameras.