Some applications of 2-D and 3-D photogrammetry during laboratory experiments for hydrogeological risk assessment

Abstract

(2015) Some applications of 2-D and 3-D photogrammetry during laboratory experiments for hydrogeological risk assessment, Geomatics, Natural Hazards and Risk, 6:5-7, 473-496, DOI: 10.1080/19475705.2014 Scaled-down flume tests are largely used to support investigations for the assessment of hydrogeological risk. Achieved outcomes can be integrated to numerical analyses for the study of unstable slope collapse, debris transport, and hydrological models in general. In the set-up of such simulation platforms, a relevant role has to be given to the Spatial Sensor Network (SSN) which is in charge of collecting geo-referenced, quantitative information during experiments. Photogrammetry (including 3-D imaging sensors) can play an important role in SSN because of its capability of collecting information covering wide surfaces without any contact. The aim of this paper is to give an overview and some examples of the potential of photogrammetry in hydrogeological simulation experiments. After a general introduction on a few preliminary issues (sensors, calibration, ground reference, usage of imaging or ranging sensors), potential applications are classified into 2-D and 3-D categories. Examples are focused on a scaled-down landslide simulation platform, which has been developed at Tongji University (Shanghai, P.R. China).

Close-Range Photogrammetric Techniques for Deformation Measurement: Applications to Landslides

“…Single-camera (or monocular) systems may be used to carry out 2D metric reconstructions in the case of flat or quasi-flat objects (see one example in Scaioni et al 2014a) or to qualitatively highlight the deformation regions of three-dimensional objects (see Feng et al 2012). Also in Luhmann (2009), a solution to derive 3D outputs from a single-camera image sequence has been discussed, which was based on the use of special six degree-of-freedom targets.…”

“…Moreover, the information derived from SPT could be integrated with the one achievable by a sensor network of geotechnical instruments (Scaioni et al 2013b) and by other photogrammetry outputs such as DSM and lateral profiles (Scaioni et al 2014a). …”

“…The homography model can be exploited to derive 2D coordinates in object space if the object surface is flat or quasi-flat (see Scaioni et al (2014a)). In the case of non-flat surfaces, SPT may only give a qualitative output but not any metric information.…”

Image-Based Reconstruction and Analysis of Dynamic Scenes in a Landslide Simulation Facility

“…Some relevant profiles may be also extracted, as reported in Scaioni et al (2015). As mentioned above, only in the case the object is flat, the reconstruction may be completely transformed from image (2D) to object (3D) space in non-ambiguous way.…”

“…In general, applications reported in the literature may be grouped in two main categories (see Scaioni et al, 2015):…”