Comparative study on discontinuity sets analysis using 3D point clouds from terrestrial and airborne 3D laser scanner

The stability of rock slopes depends on the characterization of the rock mass and its discontinuities, which are often planar and grouped in sets with similar orientations. Manual methods for data collection on the rock mass are prone to errors, hazards, and limitations. Remote sensing techniques, such as terrestrial 3D laser scanning (TLS) and digital photogrammetry with RPAS (Remotely Piloted Aircraft Systems), have emerged as alternatives in the last decade. TLS is accurate but restricted by the ground-level perspective. RPAS allows the reconstruction of surfaces that are inaccessible to TLS using Structure from Motion (SfM), but with lower accuracy. This research proposes the digitization of a slope using RPAS and airborne 3D laser scanning, using 3DPC from TLS as ground truth. The comparison of the discontinuity sets obtained by both techniques will evaluate their adequacy for the geometric study of the rock mass. A case study in Alicante, Spain, is presented, analyzing two outcrops of different lithologies.