Small Unmanned Aircraft System (sUAS) mapping.
Photos are acquired with a sUAS equipped with a programmable flight controller, Global Navigation Satellite System (GNSS), compass, and camera. A mission is uploaded to the flight controller that uses a set of waypoints to fly a pattern with sufficient photo overlap for photogrammetric processing.
Ground Control Points (GCPs)
Ground Control Points are used to georeference the photogrammetry data to world coordinates. This is accomplished by placing targets on the ground that will appear in the photos. The coordinates for the targets are recorded with a Real Time Kinematic (RTK) GNSS. The accuracy of the RTK GNSS is around 1 centimeter. The accuracy of the photogrametric data is dependent on resolution. Resolution being affected by the focal length of the camera and the altitude of the flight. In the U.S. max altitude is 400 feet. Typical resolutions are between 1 to 4.5 centimeters.
Photogrammetry software is used to process the photos and GCPs to produce depth maps, point clouds, 3D models, Digital Surface Models (DSMs), and ortho photos. This data can be used for measuring distance, area, and volume. It can also be exported for use with Computer-Aided Design (CAD) and Geographic Information System (GIS) software.