GNGTS 2016 - Atti del 35° Convegno Nazionale

GNGTS 2016 S essione 2.3 427 - extension of survey area; - focalization and positioning of Ground Control Points (GCP) and definition of Ground Sample Distance (GSD); - timing, data and execution of the flight. Results. The flight plan has been designed to optimize the 3D restitution of the buildings in the urbanized areas. This result has been obtained from extraction of the point cloud of buildings. Objects (like buildings) have been extracted from non-ground points. About investigated area, the point cloud is based on 46,555,492 points as derived from DEM. It has been possible to derive extensively height and floors number for each building within test area. Several cases are reported in order to show the main results of the work. First, two cases of damage are reported in order to show the ability of the procedures to survey different damage cases. Obviously, the results should be considered as the first application of the procedures. Finally, the geometrical characteristics of several building in aggregate are reported. Dimensional parameters from the image have been extracted (Fig. 3), classified and compared with classical approach. The results show that the considered integrated method leads to results far better if compared to classical approaches. The survey has been able to define the geometrical characteristics of each single building and its aggregate. For each building, number of storeys, storey height, floor area have been accurately identified. Structural characteristics of buildings have been easily identified from direct survey, historical studies and existing technical design and literature. Fig. 1 – The first case is the total collapse of roof. Fig. 2 – The second case is the partial collapse of the roof. Fig. 3 – Dimensional parameters extracted from the image.