Abstract: With the development of the tilt photography technology of the unmanned aerial vehicle (UAV), it provides a solution to the some difficult work in earthwork measurement, such as terrain limitation, time-consuming and labor-intensive. In this paper, a method of earthwork calculation is described with UAV tilt photography supporting by PhotoScan software. The classification method of point cloud and the value correction method of non-ground point elevation are introduced. By analyzing the ground control points, point cloud classification methods and non-ground point elevations, this paper proposes three principles for optimizing non-ground point layout. The accuracy of the earthwork calculation of tilt photography is verified with the real-time kinematic (RTK) GPS method. The result shows that the use of UAV tilt photography technology in earthwork calculation can not only simplify the on-field and in-door survey work, but also save cost. The accuracy of earthwork calculation can be improved through properly setting ground control points, improving point cloud classification, correct non-ground point elevation.

Key words: unmanned aerial vehicle (UAV), tilt photogrammetry, earthwork calculation, earthwork accuracy, PhotoScan