An Object-Oriented Approach to the Classification of Roofing Materials Using Very High-Resolution Satellite Stereo-Pairs

The availability of multispectral images, with both high spatial and spectral resolution, makes it possible to obtain valuable information about complex urban environment, reducing the need for more expensive surveying techniques. Here, a methodology is tested for the semi-automatic extraction of buildings and the mapping of the main roofing materials over a urban area of approximately 100 km², including the entire city of Bologna (Italy). The methodology follows an object-oriented approach and exploits a limited number of training samples. After a validation based on field inspections and close-range photos acquired by a drone, the final map achieved an overall accuracy of 94% (producer accuracy 79%) regarding the building extraction and of 91% for the classification of the roofing materials. The proposed approach proved to be flexible enough to catch the strong variability of the urban texture in different districts and can be easily reproducible in other contexts, as only satellite imagery is required for the mapping

Multitemporal Thermal Imagery Acquisition and Data Processing on Historical Masonry: Experimental Application on a Case Study

The recent improvement of infrared image quality has increased the use of thermography as a non-destructive diagnostic technique. Amongst other applications, thermography can be used to monitor historic buildings. The present work was carried out within the framework of the Horizon 2020 European project SHELTER, which aims to create a management plan for cultural heritage subject to environmental and anthropogenic risk. Among the chosen case studies is the Santa Croce Complex in Ravenna (Italy), which is exposed to different hazards, including flooding. The church has a peculiar architecture that develops below the street level, so the internal walls are affected by the deterioration caused by rising humidity. In such a case of advanced degradation, passive thermography cannot be used to its full potential. For this reason, an innovative methodology involving active thermography was first developed and validated with laboratory tests. Secondly, we conducted its first application to a real case study. With this purpose, an active thermography survey with forced ventilation was carried out to enhance different stages of material degradation by means of automatic classification of multitemporal data. These experiments have resulted in a method using an active thermal survey in a high moisture content environment to detect masonry degradation

ZYGOMA IMPLANT-SUPPORTED PROSTHETIC REHABILITATION OF A PATIENT AFTER SUBTOTAL BILATERAL MAXILLECTOMY

This clinical report describes the successful implant-supported prosthetic rehabilitation of a patient who underwent subtotal bilateral maxillectomy for an oral squamous cell carcinoma with a consequent wide defect interesting the whole hard palate and most of the soft palate, causing a large opening that directly connects the oral cavity to the nasal fosse bilaterally. The innovative aspect of this case is represented by the realization of a obturator prosthesis supported by just three zygoma implants. The maxillary bone had been largely excised by radical surgery. Despite the resection had a complete oncological success and the patient was free of disease after 24 months follow up, the patient experienced severe speech and deglutition deficit due to the iatrogenic large oro-antral communication. Three zygoma implants have been positioned, two trough the right maxillary bone and, owing the wide lack of bone, just one on the left side. No mucogengival surgery was necessary around the zygoma implants. The obturator prosthesis was stabilized by the three implants and the patient\u2019s oral function as well as quality of life widely improved. The results show that zygoma implants could represent a viable surgical option to obtain a satisfactory oral function rehabilitation even in case of extensive maxillary defect

Il telerilevamento satellitare nella gestione delle emergenze da catastrofi naturali: l’alluvione tra l'Enza e il Parma del dicembre 2017

Le alluvioni sono tra le principali catastrofi che gli stati europei hanno dovuto affrontare negli ultimi anni. In questo contesto, le tecniche di osservazione della Terra sono diventate strumenti essenziali per la gestione di questo tipo di rischio. Il telerilevamento satellitare consente infatti l’individuazione delle aree allagate e fornisce preziose informazioni sull'intensità, sull’evoluzione degli allagamenti. Le immagini SAR e le immagini ottiche costituiscono dunque il mezzo più efficiente e rapido per la raccolta dei dati utili ad analisi in pre- e post-evento. Il programma di osservazione della Terra “Copernicus”, gestito dalla Commissione Europea, è stato concepito per fornire informazioni accurate, aggiornate e facilmente accessibili al fine di una corretta gestione dell’ambiente e di situazioni di emergenza di origine naturale o antropica. I satelliti della missione Sentinel sono stati creati per raggiungere gli obiettivi del programma fornendo immagini multispettrali e radar di alta qualità e liberamente scaricabili. Il presente elaborato di tesi presenta un’analisi dell’evento alluvionale che ha colpito la regione Emilia-Romagna nel dicembre 2017. Tra il 10 e l’11 dicembre, piogge eccezionali hanno causato esondazioni e tracimazioni di alcuni corsi d'acqua. Lungo il fiume Enza, l’onda di piena ha danneggiato in tre punti l’argine provocando l’esondazione nella frazione di Lentigione (RE), coinvolgendo l’abitato e la campagna limitrofa. Alcune tracimazioni del Parma sono state registrate nella cittadina di Colorno (PR). L’obiettivo dello studio è la delineazione degli allagamenti causati dagli eventi eccezionali sopra descritti, attraverso l’utilizzo dei dati Sentinel. Sono state analizzate sia immagini radar della missione Sentinel-1, sia immagini multispettrali della missione Sentinel-2, sia per mappare l’area colpita durante l’evento che per monitorare gli effetti del disastro nel periodo successivo all’evento

Cross-sensors analysis of multispectral Earth observation data for environmental monitoring

Time Series Analysis of multispectral satellite data offers an innovative way to extract valuable information of our changing planet. This is now a real option for scientists thanks to data availability as well as innovative cloud-computing platforms, such as Google Earth Engine. The integration of different missions would mitigate known issues in multispectral time series construction, such as gaps due to clouds or other atmospheric effects. With this purpose, harmonization among Landsat-like missions is possible through statistical analysis. This research offers an overview of the different instruments from Landsat and Sentinel missions (TM, ETM, OLI, OLI-2 and MSI sensors) and products levels (Collection-2 Level-1 and Surface Reflectance for Landsat and Level-1C and Level-2A for Sentinel-2). Moreover, a cross-sensors comparison was performed to assess the interoperability of the sensors on-board Landsat and Sentinel-2 constellations, having in mind a possible combined use for time series analysis. Firstly, more than 20,000 pairs of images almost simultaneously acquired all over Europe were selected over a period of several years. The study performed a cross-comparison analysis on these data, and provided an assessment of the calibration coefficients that can be used to minimize differences in the combined use. Four of the most popular vegetation indexes were selected for the study: NDVI, EVI, SAVI and NDMI. As a result, it is possible to reconstruct a longer and denser harmonized time series since 1984, useful for vegetation monitoring purposes. Secondly, the spectral characteristics of the recent Landsat-9 mission were assessed for a combined use with Landsat-8 and Sentinel-2. A cross-sensor analysis of common bands of more than 3,000 almost simultaneous acquisitions verified a high consistency between datasets. The most relevant discrepancy has been observed in the blue and SWIRS bands, often used in vegetation and water related studies. This analysis was supported with spectroradiometer ground measurements

Cross-Sensors Comparison of Popular Vegetation Indexes From Landsat TM, ETM=, OLI, and Sentinel MSI for Time-Series Analysis Over Europe

In the perspective of long and dense time-series analyses for environmental monitoring applications, this article discusses a cross-comparison analysis between the different instruments of Landsat and Sentinel missions [thematic mapper (TM), enhanced thematic mapper plus (ETM+), operational land imager (OLI), and multispectral instrument (MSI)]. The level-2 surface reflectance (SR) products were considered (in particular, the reprocessed Collection-2 for Landsat). The calibration coefficients for four of the most popular vegetation indexes [normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), soil adjusted vegetation index (SAVI), and normalized difference moisture index (NDMI)] were estimated, with the aim of harmonizing and minimizing radiometric differences for the combined use of these sensors. For this purpose, more than 20000 pairs of images almost simultaneously acquired (±1-day tolerance window) were selected over a period of several years (depending on the lifespan overlap of every sensor pair). Vegetation indices (VIs) were computed for each image, and for each cross comparison, 100 random extractions of 300 000 sample pixels were performed all over the European continent. Linear transformation functions for each VI and between each sensor couple were computed by regression analyses, also assessing the repeatability of the estimation. Furthermore, the stability over time of the obtained coefficients was assessed when enough years of corresponding observations are available

Multitemporal Thermal Imagery Acquisition and Data Processing on Historical Masonry: Experimental Application on a Case Study

The recent improvement of infrared image quality has increased the use of thermography as a non-destructive diagnostic technique. Amongst other applications, thermography can be used to monitor historic buildings. The present work was carried out within the framework of the Horizon 2020 European project SHELTER, which aims to create a management plan for cultural heritage subject to environmental and anthropogenic risk. Among the chosen case studies is the Santa Croce Complex in Ravenna (Italy), which is exposed to different hazards, including flooding. The church has a peculiar architecture that develops below the street level, so the internal walls are affected by the deterioration caused by rising humidity. In such a case of advanced degradation, passive thermography cannot be used to its full potential. For this reason, an innovative methodology involving active thermography was first developed and validated with laboratory tests. Secondly, we conducted its first application to a real case study. With this purpose, an active thermography survey with forced ventilation was carried out to enhance different stages of material degradation by means of automatic classification of multitemporal data. These experiments have resulted in a method using an active thermal survey in a high moisture content environment to detect masonry degradation

Soccer-related facial fractures: postoperative management with facial protective shields.

Facial fractures are one of the most common orofacial injury sustained during participation in sporting events.The frequency of maxillofacial lesions varies according to the popularity that each sport has in a particular country. Soccer is the most popular sport in Italy, and it is responsible for a large number of facial traumas.Traumas and fractures in soccer mainly involve the zygomatic and nasal regions and are especially caused by direct contact that takes place mainly when the ball is played with the forehead. In particular, elbow-head and head-head impacts are the most frequent dangerous contacts.Soccer is not a violent sport, and the use of protective helmets is not allowed because it could be dangerous especially when players play the ball with the head. The use of protective facial shields are exclusively permitted to preserve players who underwent surgery for facial fractures.The use of a facial protection mask after a facial fracture treatment has already been reported. This article describes a clinical experience of management of 4 soccer-related facial fractures by means of fabrication of individual facial protective shields