Photogrammetry is a technique to obtain 2D maps from a series of aerial land photographs. Properly overlapping images is also possible to retrieve depth and elevation ( 3D). With the drones flying precision and a few ground reference points, measured with high precision GPS systems, it is possible to obtain models with an error of a very few centimeters. This technology is useful in mining, construction, archeology and other fields .
Using multispectral cameras (infrared + visible) it is possible to detect variations in vegetation and water stress , this being ideal for agriculture.