With almost all drones today, to get globally accurate 3D data, ground control points must be set around a site. A 100-acre site requires about 10 GCPs, which take a two-person team approximately two hours to place. The flight over that 100-acre site might take a half hour, meaning that 80 percent of the labor time is spent just laying GCPs.
For companies performing hundreds of surveys per year, time spent on GCPs adds up. Last year, one of our clients, Komatsu, realized it was spending hundreds of man-hours every month setting up, maintaining, and retrieving GCPs. In no uncertain terms, GCPs were slowing it down.