A Comparison Among Different Optimization Levels In 3d Multi-Sensor Models. A Test Case in Emergency Context: 2016 Italian Earthquake

Abstract

ABSTRACT:In sudden emergency contexts that affect urban centres and built heritage, the latest Geomatics technique solutions must enable the demands of damage documentation, risk assessment, management and data sharing as efficiently as possible, in relation to the danger condition, to the accessibility constraints of areas and to the tight deadlines needs. In recent times, Unmanned Vehicle System (UAV) equipped with cameras are more and more involved in aerial survey and reconnaissance missions, and they are behaving in a very cost-effective way in the direction of 3D documentation and preliminary damage assessment. More and more UAV equipment with low-cost sensors must become, in the future, suitable in every situation of documentation, but above all in damages and uncertainty frameworks. Rapidity in acquisition times and low-cost sensors are challenging marks, and they could be taken into consideration maybe with time spending processing. The paper will analyze and try to classify the information content in 3D aerial and terrestrial models and the importance of metric and non-metric withdrawable information that should be suitable for further uses, as the structural analysis one. The test area is an experience of Team Direct from Politecnico di Torino in centre Italy, where a strong earthquake occurred in August 2016. This study is carried out on a stand-alone damaged building in Pescara del Tronto (AP), with a multi-sensor 3D survey. The aim is to evaluate the contribution of terrestrial and aerial quick documentation by a SLAM based LiDAR and a camera equipped multirotor UAV, for a first reconnaissance inspection and modelling in terms of level of details, metric and non-metric information.

Rapid Mapping for Built Heritage at Risk Using Low-Cost and Cots Sensors. A Test in the Duomo Vecchio of San Severino Marche

“…In the context of a multiscale approach, especially for the Rapid Mapping of the Built Heritage, in at risk scenarios is crucial to adopt different strategies to achieve a higher detail of areas of specific interest. For example, the rapid growth in the use of UAVs for aerial photogrammetry is having a big impact also in these scenarios Chiabrando et al, 2017;Fernandez Galarreta et al, 2015) creating new perspectives for the management of future events and new operation procedures. However, in this work the focus will be set on different types of sensors and considering a different scale (mainly architectural) and the aerial contribution will not be considered in this part of research.Different groups of researchers have already investigated the use of low-cost and COTS sensors in different scenarios (Chiabrando et al, 2017;Das et al, 2015;Kolev et al, 2014;Micheletti et al, 2015), however lot of questions are still open and the definition of operative standards in this field is still missing.…”

DEM-Based UAV Flight Planning for 3D Mapping of Geosites: The Case of Olympus Tectonic Window, Lesvos, Greece

“…The automatically pre-designed photogrammetric planning and control of UAV flights plays an essential role in providing quality images and thus good cartographic results. The quality of a 3D model depends on flight planning characteristics, such as the geometrical parameters of: (I) ground sampling distance (GSD) and (II) front and side overlap, and the UAV's flight parameters, which consist of (I) the angle of the camera, (II) the height of the flight, (III) the orientation of the aircraft and (IV) the path that the UAV follows [30][31][32].…”

Survey Methods for Seismic Vulnerability Assessment of Historical Masonry Buildings

“…In emergency contexts that affect built heritage, Geomatics techniques enable the demands of documentation, risk assessment, management, in relation to danger condition (Chiabrando, 2017). The survey of areas devastated by earthquakes presents some specific characteristics that differentiate it from the conventional schemes and standardized methods traditionally used.…”