Metrological Considerations Regarding the Positioning of Terrestrial Laser Scanners for the Stability Assessment of Buildings in Emergency Conditions

After an earthquake, rescuers and technicians need to quickly assess the buildings' stability, define safe intervention strategies, and design provisional structures that prevent further damage to the structures. In this paper the authors aim to investigate the in-field metrological characteristics of a Terrestrial Laser Scanner, used to assess the structural state of buildings damaged by an earthquake. In particular, the effect of the instrument's position with respect to the building will be deepened, stressing the ability of the scanner to acquire points from very narrow angles of incidence. The study allows the Terrestrial Laser Scanner to single out where the positioning effect of the instrument is negligible, from the point of view of the measurement accuracy, and other areas where the measurement uncertainty begins to be affected. These results can be useful to the people involved in rescue to evaluate the reliability of data also in cases when standards and literature suggestions are difficult to realize.