Applicability and limitations of terrestrial and UAV-based remote sensing techniques for slope rock mass characterization

ABSTRACT: This study evaluates the applicability and limitations of terrestrial and UAV-based remote sensing techniques in rock mass assessments. Terrestrial laser scanning (TLS) and two portable laser scanners (HandyScan and GeoSLAM) were employed as ground-based methods, offering high-resolution data and detailed local 3D models. UAV-based LiDAR and photogrammetry techniques were integrated to capture slope-scale topographic variations and rock mass structure. These methods were evaluated for their ability to capture key rock mass parameters such as RQD, joint spacing, aperture, roughness, and joint orientation. Each method's accuracy, point density, data acquisition time, and suitability for varied geological conditions were analyzed. TLS and HandyScan provided high-resolution data, making them suitable for detailed surface assessments, while GeoSLAM enabled efficient scanning of complex terrains with mobile capabilities. UAV-based LiDAR and photogrammetry allowed rapid and broad data collection, particularly in inaccessible areas, but faced limitations in capturing fine-scale features in vegetated areas. The findings highlight the strengths and limitations of each technique and provide recommendations for their application for rock mass characterization and slope stability analysis in slope cut assessments.