Fig. 1. Schematic of grid simplification

Fig. 2. Schematic of inverse-distance-weighted interpolation

Fig. 3. Result of uncontrolled interpolation area

Fig. 4. Result of block inverse-distance-weighted interpolation

Fig. 5. Photograph of actual coal stockpile

Fig. 6. Planning graph of air route

Fig. 7. Original point cloud of coal stockpile

Fig. 8. Results of point cloud of coal stockpile after large-scale noise filtering

Fig. 9. Result of MLS smoothing

Fig. 10. Result of adaptive grid simplification of point cloud

Fig. 11. Reconstructed greedy-triangulation surface

Fig. 12. Reconstructed greedy-triangulation surface after interpolation

Fig. 13. Micro-element volume calculation model

Fig. 14. Result of volume calculation