Impact of the grid cell size and interpolation methods on earthwork volume calculation

Technologies of massive spatial data acquisition from air, compared to a classical terrain measurement, enables an acquisition of large amounts of data in shorter time and with comparable quality. Unmanned aerial vehicle (UAV) photogrammetry is increasingly used in the area of the earthwork volumes determination of landfill or excavation of the building material. Dense multi-image matching obtains high-density point cloud. The input data for the earthwork volumes calculations is a filtered point cloud. The earthwork volume calculations are calculated with the method of surface comparisons of two term measurements, created by a triangulated irregular network (TIN) or grid network. The impacts of different methods for surface interpolation and grid cell size on the earthwork volume calculation are analysed. Reference quantity is the volume, calculated from TIN surfaces. Good interpolation methods and appropriate grid cell sizes are determined with the comparison of volumes from grid and TIN surfaces. The difference between volumes should not exceed 5%.