Drones useful for surveying are equipped with onboard cameras that take photos of the ground from different points in the air. Images are tagged with geo-coordinates that are captured by a GNSS sensor on the drone indicating exactly where that image is situated in space. The image is ? Click for more info -checked? against known points on the floor using RTK or PPK processing (we?ll dive in to the difference between RTK and PPK processing down the road).
A single drone flight collects hundreds or even thousands of images that are then processed with photogrammetry software that ?stitches? the images together to create geo-referenced orthomosaics or 3D types of a work site. Those 3D maps can then be analyzed to get detailed information regarding project quantities, distances, elevations, and inventory. By collecting this data at regular intervals and comparing those maps to design files and previous surveys, companies can confidently and accurately track changes and progress. Because drones can fly at a lower altitude than manned aircraft or satellites, they could capture highly detailed information considerably faster than and less expensive when compared to a base and rover. Drones are also able collect aerial images from terrain that may be hazardous and dangerous for a human to survey manually on foot.