Donatella Dominici

Development of a Software to Plan UAVs Stereoscopic Flight: An Application on Post Earthquake Scenario in L’Aquila City

On April 6, 2009, an earthquake hit the historic center of L’Aquila city, hundreds of victims, thousands of collapses. During the post-emergency a continuous monitoring of all building is crucial in order to guarantee that each structure at least will not worsen its stability until the final reconstruction is completed. So detailed surveying of all building is performed using different geomatic techniques as total stations, land photogrammetry, and laser scanners. Even if all these techniques can perfectly respond to many crucial post hazard needs, there are still many monitoring that cannot be completely carried on with traditional techniques. For these reasons, in this work, the advantages of using multirotor UAVs will be illustrated; UAVs can be fully remote controlled and so the geometry of photogrammetric image acquisition can be imposed.

An application of COSMO-Sky Med to coastal erosion studies

Abstract Started in 2009, the COSMOCoast project aims to the investigation of the potential of Remote Sensing in support to the management of coastal areas. Particular attention is paid to the contribution of data acquired from the COSMO-SkyMed constellation, in view of their frequency of acquisitions and ground resolution; in particular this paper aims at assessing the potential of COSMO-SkyMed data for coastline delineation. The results are conceived to be of particular interest for public administration bodies in charge of coastal defense. Keywords: Remote Sensing, Coastal Zones Management, COSMO-SkyMed.

Automatic three-dimensional features extraction: The case study of L'Aquila for collapse identification after April 06, 2009 earthquake

Abstract This paper illustrates an innovative methodology for post-earthquake collapsed building recognition, based on satellite-image classification methodologies and height variation information. Together, the techniques create a robust classification that seems to yield good results in this application field. In the first part of this study, two different feature extraction methodologies were compared, based respectively on pixel-based and object-oriented approaches. Then the classification results of the most accurate classification methodology. obtained on an eight band WorldView-2 monoscopic image, were completed with height variation information before and after the event. The height difference is calculated, comparing a photogrammetric DSM, obtained using a photogrammetric rigorous orbital model on some EROS-B 0.7 metre across-track stereopairs with a ‘roof model’ before the earthquake.

Development of a software to optimize and plan the acquisitions from UAV and a first application in a post-seismic environment

Abstract An Unmanned Aerial Vehicle (UAV) is an aircraft without a human pilot on board. UAVs allow close-range photogrammetric acquisitions potentially useful for building large-scale cartography and acquisitions of building geometry. This is particularly useful in emergency situations where major accessibility problems limit the possibility of using conventional surveys. Presently, however, flights of this class of UAV are planned based only on the pilots experience and they often acquire three or more times the number of images needed. This is clearly a time-consuming and autonomy-reducing procedure, which is certainly detrimental when extensive surveys are needed. For this reason new software, to plan the UAVs survey will be illustrated.

Remote Sensing of Urban Microclimate Change in L’Aquila City (Italy) after Post-Earthquake Depopulation in an Open Source GIS Environment

This work reports a first attempt to use Landsat satellite imagery to identify possible urban microclimate changes in a city center after a seismic event that affected L’Aquila City (Abruzzo Region, Italy), on 6 April 2009. After the main seismic event, the collapse of part of the buildings, and the damaging of most of them, with the consequence of an almost total depopulation of the historic city center, may have caused alterations to the microclimate. This work develops an inexpensive work flow—using Landsat Enhanced Thematic Mapper Plus (ETM+) scenes—to construct the evolution of urban land use after the catastrophic main seismic event that hit L’Aquila. We hypothesized, that, possibly, before the event, the temperature was higher in the city center due to the presence of inhabitants (and thus home heating); while the opposite case occurred in the surrounding areas, where new settlements of inhabitants grew over a period of a few months. We decided not to look to independent meteorological data in order to avoid being biased in their investigations; thus, only the smallest dataset of Landsat ETM+ scenes were considered as input data in order to describe the thermal evolution of the land surface after the earthquake. We managed to use the Landsat archive images to provide thermal change indications, useful for understanding the urban changes induced by catastrophic events, setting up an easy to implement, robust, reproducible, and fast procedure.

Reliability and Precision of a Network for Monitoring Very Slow Movements with a Total Station

This paper describes the monitoring system planned to measure the displacements of an extremely slow landslide in an alpine glacial valley in Northern Italy. Because of the smallness of the displacements, normally less than 1 cm/year, great attention has been paid to evaluate the reliability of the measurements by evaluating their precision and accuracy. For this purpose it was essential to make the system redundant by measuring the displacements with at least two different techniques: the inclinometers to monitor the subsurface displacements and the Total Station for measuring the surface displacements. With the increase of redundancy of the measures, there are more information to describe the landslide in terms of displacements, directions and rate, both superficial and deep. In this way, movements are better investigated and it is possible to highlight eventual disagree between the different techniques of measurement and improve the result’s accuracy. The paper focuses mainly on the characteristics of the network used with the Total Station, in order to define how they affect the precision and accuracy of the measurements. Thus, the aim of this research has been to derive some conclusions about the optimal monitoring surveying network in terms of reliability and precision, compatible with the type of slope movements and the morphology of the site. The strategies of elaboration and results obtained are presented in this paper.

Integrating geomatics and structural investigation in post-earthquake monitoring of ancient monumental Buildings

Abstract The old city center of L’Aquila is rich in historical buildings of considerable merit. On April 6th 2009 a devastating earthquake caused significant structural damages, affecting especially historical and monumental masonry buildings. The results of a study carried out on a monumental building, former headquarters of the University of L’Aquila (The Camponeschi building, XVI century) are presented in this paper. The building is situated in the heart of the old city center and was seriously damaged by the earthquake. Preliminary visual damage analysis carried out immediately after the quake, clearly evidenced the building’s complexity, raising the need for direct and indirect investigation on the structure. Several non-destructive test methods were then performed in situ to better characterize the masonry typology and the damage distribution, as well. Subsequently, a number of representative control points were identified on the building’s facades to represent, by their motion over time, the evolution of the structural displacements and deformations. In particular, a surveying network consisting of 27 different points was established. A robotic total station mounted on top of a concrete pillar was used for periodically monitoring the surveying control network. Stability of the pillar was checked through a GNSS static survey repeated before any set of measurements. The present study evidences the interesting possibilities of combining geomatics with structural investigation during post-earthquake monitoring of ancient monumental buildings.

The survey of the Basilica di Collemaggio in L’Aquila with a system of terrestrial imaging and most proven techniques

ABSTRACT The proposed job concerns the evaluation of a series of surveys carried out in the context of a campaign of studies begun in 2015 with the objective of comparing the accuracies obtainable with the systems of terrestrial imaging, compared to unmanned aerial vehicle imaging and laser scanner survey. In particular, the authors want to test the applicability of a system of imaging rover (IR), an innovative terrestrial imaging system, that consists of a multi-camera with integrated global positioning system (GPS)/global navigation satellite system (GNSS) receiver, that is very recently released technique, and only a few literature references exist on the specific subject. In detail, the IR consists of a total of 12 calibrated cameras – seven “panorama” and five downward-looking – providing complete site documentation that can potentially be used to make photogrammetric measurements. The data acquired in this experimentation were then elaborated with various software packages in order to obtain point clouds and a three-dimensional model in different cases, and a comparison of the various results obtained was carried out. Following, the case study of the Basilica di Santa Maria di Collemaggio in L’Aquila is reported; Collemaggio is an UNESCO world heritage site; it was damaged during the seismic event of 2009, and its restoration is still in progress.

A New Enhancement Filtering Approach for the Automatic Vector Conversion of the UAV Photogrammetry Output

In the last decades the photogrammetry has undergone interesting innovation, both in terms of data processing and acquisition mode, to allow obtaining detailed 3D models useful for complete survey and important support for the management and recovery of cultural heritage and buildings. However, despite recent developments, the main photogrammetry outputs are raster data (ortophoto and DEM) and point clouds characterized by high informative content, but they are not typically extracted automatically. Automated feature detection is yet manual, time-consuming procedure and an active area of research. The raster to vector conversion is not direct, but transformations must be performed on the input data to convert the pixel values into features. Always, segmentations are preceded by filter technique to remove noise and to improve the conversion phase. However, remote sensing data and especially UAV photogrammetry output are the most complex to treat because of their heterogeneity (presence of different objects and shapes), the nature of sensor used and the different scale. In this work we experiment new enhancement filter to improve the automatic extraction of vector information for a UAV photogrammetry results of the facing walls of eminent church, symbol of the city of L’Aquila, the” Basilica of Santa Maria di Collemaggio”.

Using Space-Based Technology for Smart Resource Management during Disaster Early Warnings

To improve the decision process of first responders just before and just after a disaster, effective access to distributed unstructured disaster information and an infrastructure for precise and accurate disaster information access and retrieval could represent new and important tools. Moreover, they could help improve the performance of disaster prediction tools developed in any country in the world. This chapter describes a system based on integration of space and terrestrial technologies that aims to provide useful information to first responder organizations for smart management of disasters, both in the early warning phase and just after it.