Identifying collapsed buildings

THE WORK TO RECOVER AND REBUILD FOLLOWING an earthquake requires reliable information on the condition of structures in the affected areas. In developed areas, efforts to gather this information can be time-consuming and prone to errors, often resulting in incomplete or inaccurate information. A new, software-based methodology to recognize collapsed buildings utilizes classification of satellite images combined with height variation information. The methodology was demonstrated in a full-scale, real-life scenario by a team led by Prof. Valerio Baiocchi of the University of Rome. According to Baiocchi, the team’s work was intended to demonstrate the methodology on actual data available for the entire city of L’Aquila in the Abruzzo region of central Italy, in an actual and complete simulation of quick damage assessment in a real emergency. The team utilized satellite imagery of the city of L’Aquila, which experienced a magnitude 6.3 earthquake on April 6, 2009. The work demonstrated a robust classification of collapsed structures that was completed quickly and with good confidence

A new methodology to manage Italian geodetic datums of the cadastral systems and of the historic maps

Cadastral maps represent the result of the highest scale survey of any region. They are not topographic maps. Their goal is to show the property system of the mapped area, so any topographic element that is important for this aspect is shown while others often omitted. Historical cadastral sheets provide valuable information about not only the natural and built environment but also about some aspects of the society of the time of the survey. Because of their high scale, their creation is extremely expensive. Even the updating of the cadastre claims considerable funds from the state budgets. That is why the coordinate system, the geodetic basis of a cadastral work is rarely changed. Re-ambulation is often made on the basis of the older version, following their geodetic and topographic 'skeleton'. The main period of the cadastral works in Europe was the first two thirds of the nineteenth century. Countries that gained their independency after this period have quite complicated cadastral systems, more or less preserving the political distribution of their lands of the time of cadastral mapping. Besides Germany, Italy provides the best example to this. Concerning Italy, the complete unification of the country was in 1870. To this time, a large part of the Apennine Peninsula was covered by cadastral surveys, mainly carried out by Piedmont, the Kingdom of Naples, and the Papal State as reported by Frazzica et al. (Geophysical Research Abstracts 11:4791, 2009). After the WWI, territorial gains from the former Habsburg Empire resulted three new cadastral systems to be incorporated (one of them 'lost' after WWII). Together with them, nowadays, Italy has 31 major ("grandi origini") and more than 800 smaller, local ("piccole origini") cadastral systems; all of them have its own projection origin (Fig. 1; Baiocchi et al. 2011). At some smaller parts of the country, the modern national map grid system was later introduced and applied as reported by Moncada (1948), Bonifacino (1953), and Giucucci (Rivista del Catasto e dei Servizi Tecnici Erariali 8(2):109-113, 1953). Fortunately, the story of the related geodetic datums was simplified prior to nowadays. Of course, the abovementioned systems had several trigonomentric networks as geodetic bases. In the first decades of the twentieth century, however, the Italian Institute of Military Geography (Istituto Geografico Militare; I.G.M) developed four geodetic networks, all on the Bessel 1841 ellipsoid; the Genova 1902 (Fig. 2), the old Monte Mario (Fig. 3), the Castanea delle Furie 1910, and the Guardia Vecchia (Fig. 4) datums, for northern, central, and southern Italy and Sardinia, respectively (Mori 1922). However, these systems were independent ones; afterward, one of them, the Genova 1902 datum, was extended to cover other parts of the country. Outside of northern Italy, the original area of this datum, the coordinates of the basepoint, and the cadastral system origins were transformed from the locally valid network to Genova 1902 datum. The present paper aims to estimate the accuracy of this extension of that system and to describe the parameters of the other systems for GIS applications, thus offering a tool for future, higher accuracy methods to fit the cadastral maps of southern Italy and Sardinia to modern grids. This can be useful also to convert some older technical maps that were referred to the same geodetic datums. © 2013 Società Italiana di Fotogrammetria e Topografia (SIFET)

Horizontal accuracy assessment of very high resolution Google Earth images in the city of Rome, Italy

Google Earth (GE) has recently become the focus of increasing interest and popularity among available online virtual globes used in scientific research projects, due to the free and easily accessed satellite imagery provided with global coverage. Nevertheless, the uses of this service raises several research questions on the quality and uncertainty of spatial data (e.g. positional accuracy, precision, consistency), with implications for potential uses like data collection and validation. This paper aims to analyze the horizontal accuracy of very high resolution (VHR) GE images in the city of Rome (Italy) for the years 2007, 2011, and 2013. The evaluation was conducted by using both Global Positioning System ground truth data and cadastral photogrammetric vertex as independent check points. The validation process includes the comparison of histograms, graph plots, tests of normality, azimuthal direction errors, and the calculation of standard statistical parameters. The results show that GE VHR imageries of Rome have an overall positional accuracy close to 1 m, sufficient for deriving ground truth samples, measurements, and large-scale planimetric maps

Evaluation of the damages caused by seismic events: First tests on supporting traditional multispectral classification with DSM

Seismic damages, as a roof entirely collapsed on the ground, are very difficult to be found using only multispectral classification algorithms. The availability of high resolution stereopairs from satellite disclose new possible fields of application to estimate changes and transformations of areas following catastrophic events. Combining both techniques it is obviously possible only when stereoscopic and multispectral images are available. In this case, as for all monitoring studies, it is necessary to compare the present situation to the pre-seismic one. The pre-seismic situation can be advantageously studied by classic photogrammetric techniques based on aerial frames, that are available in archives managed by photogrammetric companies and local government agencies. But it is also possible to extract the pre-seismic morphology from digital maps, containing the three-dimensional characteristics of the buildings. The present research tries to: a) improve the digital surface model extracted from Ikonos satellite images covering an area of central Italy (Foligno, Umbria), through a pre-treatment of images and a manual editing b) study the best DSM models to improve the detection of height difference, mainly in urban areas, and evaluate the results of the classification of land cover as further data to detect changes in building shape. DSM obtained by three-dimensional maps have been compared with DSM extracted directly from aerial stereo-pairs using different approaches. In the area under study a seismic event happened in September of the '97 causing relevant damages to different urbanized centres of the area

Integrated surveying for the archaeological documentation of a neolithic site

It has been tested the applicability of integrated surveys (remote sensing, digital photogrammetry and terrestrial laser scanning (TLS)) in order to verify, through gradual and successive steps, how geomatic techniques can get 3D results with metric value combined with a quality content for an archaeological site. In particular, the data have been collected during the excavation campaign of Neolithic archaeological site in Taranto. The possibilities to scan articulated forms, in the presence of curve, concavity and convexity, and jutting parts rotate, characterized by alterations, through the acquisition of a dense points cloud makes the technique TLS needed in archaeology. Through the photogrammetric technique the laser data has been integrated concerning some details found on the site for which it has been required a higher degree of detail. The photogrammetric data has been acquired with the calibrated camera. The processing of the acquired data and their integration has been made possible to study an important archeological site, in its totality, from small scale (general site framework) to large scale (3D model with a high degree of detail) and to structure a multi-temporal database for simplified data management

Pansharpening techniques to detect mass monument damaging in Iraq

The recent mass destructions of monuments in Iraq cannot be monitored with the terrestrial survey methodologies, for obvious reasons of safety. For the same reasons, it’s not advisable the use of classical aerial photogrammetry, so it was obvious to think to the use of multispectral Very High Resolution (VHR) satellite imagery. Nowadays VHR satellite images resolutions are very near airborne photogrammetrical images and usually they are acquired in multispectral mode. The combination of the various bands of the images is called pan-sharpening and it can be carried on using different algorithms and strategies. The correct pansharpening methodology, for a specific image, must be chosen considering the specific multispectral characteristics of the satellite used and the particular application. In this paper a first definition of guidelines for the use of VHR multispectral imagery to detect monument destruction in unsafe area, is reported. The proposed methodology, agreed with UNESCO and soon to be used in Libya for the coastal area, has produced a first report delivered to the Iraqi authorities. Some of the most evident examples are reported to show the possible capabilities of identification of damages using VHR images

GIS4RISKS: Geographic information system for risk Image, safety key. A methodological contribution to optimise the first geodynamic post-event phases and to face emergencies

In this paper we provide a methodological and operative contribution aimed at optimising the first post-event phases in case of seismic and volcanic events, as an advancement of the research conducted for the GIS4RISKS project. Particularly, we underline the importance of setting up a performant GIS platform able to synergistically use and manage data and images deriving from multiple sources to promote a system where refined methodologies and procedures converge for the development of digital representations, calculation models, spatial and multi-temporal analysis, through an integration of geomatic, engineering and geographic approaches. A synthesis of the characteristics of this platform, useful for increasing savability during the emergency phases and to better tackle situations of crisis due to geodynamic events is provided and particular attention is also given to the added value that can be derived from a coordinated use of drones (Unmanned Aerial Vehicles – UAVs), permitting a rapid recovery of detailed information in hostile areas and a rigorous monitoring of the evolution of the situation, avoiding risks for operators on the fiel

Scan to BIM for 3D reconstruction of the papal basilica of saint Francis in Assisi In Italy

The historical building heritage, present in the most of Italian cities centres, is, as part of the construction sector, a working potential, but unfortunately it requires planning of more complex and problematic interventions. However, policies to support on the existing interventions, together with a growing sensitivity for the recovery of assets, determine the need to implement specific studies and to analyse the specific problems of each site. The purpose of this paper is to illustrate the methodology and the results obtained from integrated laser scanning activity in order to have precious architectural information useful not only from the cultural heritage point of view but also to construct more operative and powerful tools, such as BIM (Building Information Modelling) aimed to the management of this cultural heritage. The Papal Basilica and the Sacred Convent of Saint Francis in Assisi in Italy are, in fact, characterized by unique and complex peculiarities, which require a detailed knowledge of the sites themselves to ensure visitor’s security and safety. For such a project, we have to take in account all the people and personnel normally present in the site, visitors with disabilities and finally the needs for cultural heritage preservation and protection. This aim can be reached using integrated systems and new technologies, such as Internet of Everything (IoE), capable of connecting people, things (smart sensors, devices and actuators; mobile terminals; wearable devices; etc.), data/information/knowledge and processes to reach the desired goals. The IoE system must implement and support an Integrated Multidisciplinary Model for Security and Safety Management (IMMSSM) for the specific context, using a multidisciplinary approach

Morphological updating on the basis of integrated DTMs: study on the Albano and Nemi craters

The Colli Albani Volcano has recently developed particular interest in the geophysical community for some peculiar characteristics imputable to a recent residual volcanic activity, thus evidencing that it cannot be considered extinguished yet. On April 2006 an airborne laser scanning (ALS) survey of the Albano and Nemi craters has been carried out to obtain a high resolution digital terrain model (DTM) of the area. We have compared the accuracy of the ALS heights with those obtained by a fast GPS kinematic survey, obtaining maximum deviation within 50 cm. Then, we have integrated the ALS survey of the craters and the bathymetry of the Albano lake to achieve a complete DTM, useful for morphological studies. In addition, with a GNSS/RTK survey (July 2007) we have estimated the Albano and Nemi mean lake levels respectively at 288.16 m and 319.02 m (asl). Based on the integrated DTM and the newly estimated water level values, we have evaluated about 21.7 106 of m3 the water volume loss of the Albano lake from 1993 to 2007, with an average rate of about 1.6 106 m3/yr. © 2008, de Gruyter. All rights reserved

Historic cartography of L'Aquila city as a support to the study of earthquake damaged buildings

The city-center of L'Aquila suffered big damages from the main seismic event (6th April 2009, 3:32 a.m., local time; Ml=5.8, Mw= 6.2) of the seismic sequence that included hundreds of aftershocks (more than 30 of them 3.5<5.0) (INGV, 2009). Causes and modality of the collapse of some buildings are still under investigation. A 1:2000 map representing the center of L'Aquila city at the beginning of twentieth century was recently found and the comparison of this map with contemporary ones can help the study of the causes of the different response to seismic stress to different aged buildings. This study represents the first step to build a database of historic buildings in L'Aquila to test a potential correlation between the anti-earthquake regulations adopted over the years and the resulting damages. A comparison with post earthquakes damage map and the map of seismic zoning was performer to find all the possible combination of other parameters that together with building age can help to evaluate building vulnerability