Uncertainty modeling and simulation in terrestrial laser scanning of a slope

The simulation of Terrestrial Laser Scanner (TLS) surveys is pivotal for determiningoptimal instrument positions and ensuring measurement quality, especially in areaswith complex morphology. The proposed simulation procedure employs a geometricmodel derived from Aerial Laser Scanner point clouds to estimate permissible mea-surement errors according to instrument specifications and scanning geometry. Interrains characterized by irregular morphology and large scanning distances, beamdivergence represents a major source of error. To address this, our error model extendsexisting approaches by accounting for the elliptical shape of the laser beam footprinton the 3D surface, enabling the computation of the variance matrix for target coordi-nates in the general reference system. The variance matrix arising from beam diver-gence is computed for each mesh centroid in the absolute system, incorporatingcorrelations between coordinate components induced by beam divergence andmesh orientation. Simulations were carried out to evaluate the positioning of stationpoints and to compare expected accuracies and coverage across the test area. The mostfavorable results from each mesh are integrated to optimize station placement. Thisapproach provides a more realistic assessment of TLS survey accuracy and supportsimproved planning and instrument selection, particularly in morphologically complexcontexts such as landslide-prone slopes