Control points are distributed and measured on the area to be surveyed in order to enable precise surveying. They should be distributed along the outer edges and within the area, with a maximum distance of 100 metres between the points. With RTK , you need significantly fewer control points. It also speeds up the complex calculation process for the 3D model. You could even dispense with control points altogether and still obtain a good 3D model. However, subsequent georeferencing is then often inaccurate or error-prone. You can find out more about surveying in our guide Surveying with drones - but the right way!