Fig. 1. Deformation monitoring type. (a) Traditional discrete point deformation monitoring; (b) deformation heterogeneous monitoring using point cloud

Fig. 2. Corresponding blocks. (a) Block in Ⅰ epoch; (b) block in Ⅱ epoch

Fig. 3. Deformation object with u sub-regions

Fig. 4. R-tree structure and spatial index

Fig. 5. Vertical deformation of blocks. (a) Baseline near-quasi-attitude; (b) block deformation estimation

Fig. 6. Angle representation for blocks

Fig. 7. Deformation merge process with label. (a) Block deformation degree; (b) merger deformation; (c) deformation graph generation

Fig. 8. Simulated subsidence point clouds of epoch I and II. (a) 3D point cloud; (b) 2D projection

Fig. 9. Error estimation under different noise levels (σ) and block sizes (D)

Fig. 10. Landslide case

Fig. 11. Deformation graph of landslide. (a) Deformation graph; (b) deformation distribution

Fig. 12. Deformation distribution of different block sizes

Fig. 13. Deformation estimation by different methods. (a) Deformation graph by median method; (b) deformation distribution by median method; (c) deformation graph by maximum method; (d) deformation distribution by maximum method; (e) deformation graph by mean method; (f) deformation distribution by mean method