Reliability Assessment of Digital Terrain Models Drawn from Digital Photogrammetry

The modern techniques of Digital Photogrammetry are used to reconstruct Digital Terrain Models (DTMs) from photosets taken by commercial digital cameras. The algorithms are based on the Multiview Stereo Vision (MVS) which draw a 3D model in the space through the internal setting of the digital photosets. In this study, two open source codes, VisualSfM and CMP-MVS are used to combine the photosets to build the DTM of the Civitaluparella (CH) quarry wall. This latter is compared with the reference DTM reconstructed by a Laser Scanner device (in this application the Long-Range Topcon GLS-1500 laser scanner has been used). The comparison evidences spatial errors about +/- 0.1m along y and z directions and +/- 0.2m along x direction for the DTM drawn by the Digital Photogrammetry for the vertical quarry wall. Hence, these outcomes confirm the reliability of the Digital Photogrammetry codes as fast and cheap tool for drawing accurate Digital Terrain Models. These DTMs can be used for generating Digital Elevation Models (DEMs) for engineering geological applications such as slope stability analyses