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PAOLO ROSSI

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Dipartimento di Ingegneria "Enzo Ferrari"
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Dipartimento di Ingegneria "Enzo Ferrari"

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Pubblicazioni

2023 - Multitemporal Analysis of Slow-Moving Landslides and Channel Dynamics through Integrated Remote Sensing and In Situ Techniques [Articolo su rivista]
Parenti, Carlotta; Rossi, Paolo; Mancini, Francesco; Scorpio, Vittoria; Grassi, Francesca; Ciccarese, Giuseppe; Lugli, Francesca; Soldati, Mauro
abstract

The relationships between hillslope and fluvial processes were studied in a mountainous area of the Northern Apennines (Italy) where intermittent landslide activity has interacted for a long time with river morphodynamics. The aim of the study was to analyse such relationships in two study sites of the Scoltenna catchment. The sites were analysed in detail and monitored through time. A long-term analysis was carried out based on multitemporal photointerpretation of aerial photos. Slope morphological changes and land use modifications since 1954 were detected and compared with the evolution of the channel morphology. A short-term analysis was also performed based on two monitoring campaigns accomplished in 2021 and 2022 in order to detect possible slope displacements and channel-bed-level changes. The techniques used are global navigation satellite systems and drone photogrammetry accompanied by geomorphological surveys and mapping. The multitemporal data collected allowed us to characterise slope surface deformations and quantify morphological changes. The combination of various techniques of remote and proximal sensing proved to be a useful tool for the analysis of the surface deformations and for the investigation of the interaction between slope and fluvial dynamics, showing the important role of fluvial processes in the remobilisation of the landslide toe causing the displacement of a significant volume of sediment into the stream.

2023 - Quantifying the Loss of Coral from a Bleaching Event Using Underwater Photogrammetry and AI-Assisted Image Segmentation [Articolo su rivista]
Kopecky, K. L.; Pavoni, G.; Nocerino, E.; Brooks, A. J.; Corsini, M.; Menna, F.; Gallagher, J. P.; Capra, A.; Castagnetti, C.; Rossi, P.; Gruen, A.; Neyer, F.; Muntoni, A.; Ponchio, F.; Cignoni, P.; Troyer, M.; Holbrook, S. J.; Schmitt, R. J.
abstract

Detecting the impacts of natural and anthropogenic disturbances that cause declines in organisms or changes in community composition has long been a focus of ecology. However, a tradeoff often exists between the spatial extent over which relevant data can be collected, and the resolution of those data. Recent advances in underwater photogrammetry, as well as computer vision and machine learning tools that employ artificial intelligence (AI), offer potential solutions with which to resolve this tradeoff. Here, we coupled a rigorous photogrammetric survey method with novel AI-assisted image segmentation software in order to quantify the impact of a coral bleaching event on a tropical reef, both at an ecologically meaningful spatial scale and with high spatial resolution. In addition to outlining our workflow, we highlight three key results: (1) dramatic changes in the three-dimensional surface areas of live and dead coral, as well as the ratio of live to dead colonies before and after bleaching; (2) a size-dependent pattern of mortality in bleached corals, where the largest corals were disproportionately affected, and (3) a significantly greater decline in the surface area of live coral, as revealed by our approximation of the 3D shape compared to the more standard planar area (2D) approach. The technique of photogrammetry allows us to turn 2D images into approximate 3D models in a flexible and efficient way. Increasing the resolution, accuracy, spatial extent, and efficiency with which we can quantify effects of disturbances will improve our ability to understand the ecological consequences that cascade from small to large scales, as well as allow more informed decisions to be made regarding the mitigation of undesired impacts.

2022 - Image-Based Monitoring of Cracks: Effectiveness Analysis of an Open-Source Machine Learning-Assisted Procedure [Articolo su rivista]
Parente, Luigi; Falvo, Eugenia; Castagnetti, Cristina; Grassi, Francesca; Mancini, Francesco; Rossi, Paolo; Capra, Alessandro
abstract

The proper inspection of a cracks pattern over time is a critical diagnosis step to provide a thorough knowledge of the health state of a structure. When monitoring cracks propagating on a planar surface, adopting a single-image-based approach is a more convenient (costly and logistically) solution compared to subjective operators-based solutions. Machine learning (ML)- based monitoring solutions offer the advantage of automation in crack detection; however, complex and time-consuming training must be carried out. This study presents a simple and automated ML-based crack monitoring approach implemented in open sources software that only requires a single image for training. The effectiveness of the approach is assessed conducting work in controlled and real case study sites. For both sites, the generated outputs are significant in terms of accuracy (~1 mm), repeatability (sub-mm) and precision (sub-pixel). The presented results highlight that the successful detection of cracks is achievable with only a straightforward ML-based training procedure conducted on only a single image of the multi-temporal sequence. Furthermore, the use of an innovative camera kit allowed exploiting automated acquisition and transmission fundamental for Internet of Things (IoTs) for structural health monitoring and to reduce user-based operations and increase safety.

2022 - Influence of AGL flight and off-nadir images on UAV-SfM accuracy in complex morphology terrains [Articolo su rivista]
Aguera-Vega, F.; Ferrer-Gonzalez, E.; Carvajal-Ramirez, F.; Martinez-Carricondo, P.; Rossi, P.; Mancini, F.
abstract

In the field of geosciences and engineering, situations arise where special attention have to be paid to the planning of the UAV-photogrammetric project, that is, terrain with complex geometry and steep slopes. The use of off-nadir imagery and flights at a fixed height above ground level (AGL) are postulated as possible factors to be considered to achieve high accuracies. The objective of this study is to evaluate the influence of image angle, frontal and side overlaps, and type of flight (above mean sea level (AMSL) or AGL), on the accuracy of the dense 3 D point cloud yielded by UAV-SfM. The results obtained showed that imagery with an angle between 20° and 35° in two perpendicular flight line directions, 90/90, 90/70 or 70/70 overlap and AGL flight is the optimal combination for best accuracy and high precision. With nadir imagery, the combination of factors that gives the most accuracy results are AGL flights with a 90/70 overlap.

2022 - Integrated Geomatics Surveying and Data Management in the Investigation of Slope and Fluvial Dynamics [Articolo su rivista]
Parenti, Carlotta; Rossi, Paolo; Soldati, Mauro; Grassi, Francesca; Mancini, Francesco
abstract

In mountain environments, slope and fluvial dynamics often interact, and their relationship can be investigated through an integrated methodological approach. Landslides are a source of supplying sediments into riverbeds and can interact or interrupt the water course. Water courses can trigger or re-activate slope movements. The complexity of investigating the interaction between the two dynamics needs a complementarity of methods and techniques, combining remote and proximal sensing, geotechnical in situ surveys, and repositories and catalogue datasets. This leads to a synergistic use of all the heterogeneous data from different fields and formats. The present paper provides a literature review on the approaches and surveying procedures adopted in the investigation of slope and fluvial dynamics and highlights the need to improve the integrated management of geospatial information complemented by quality information. In this regard, we outline a geodatabase structure capable of handling the variety of geoscientific data available at different spatial and temporal scales, with derived products that are useful in integrated monitoring tasks. Indeed, the future adoption of a shared physical structure would allow the merging and synergistic use of data provided by different surveyors as well as the effective storing and sharing of datasets from a monitoring perspective.

2022 - PHOTOGRAMMETRIC AND FLUORESCENCE SOLUTIONS FOR MONITORING OF HABITAT FORMING ORGANISMS [Relazione in Atti di Convegno]
Rossi, P.; Righi, S.; Parente, L.; Castagnetti, C.; Cattini, S.; Di Loro, G.; Falvo, E.; Grassi, F.; Mancini, F.; Rovati, L.; Simonini, R.; Capra, A.
abstract

The development and testing of innovative technologies and automated data analysis methodologies offer tools for the monitoring of complex marine ecosystems and the direct and indirect effects of climate change on natural heritage. Photogrammetric methods allow precise mapping of the underwater landscape as well as detailed three-dimensional (3D) reconstruction of marine structures, improving the study of complex marine ecosystems. Moreover, fluorescence analyses can provide critical information about the health status of marine organisms. Analysing the variations in their self-fluorescence, allow for early detect changes in their physiological state. These applications provide very useful data to evaluate the health state of biodiversity-rich 3D biogenic structures and make measurements of fine-scale changes, with greater precision than existing methodologies. This contribution shows a multidisciplinary approach to the design, development, and implementation of a technological solution based on the above-mentioned optical measuring systems. Such a system is characterized by a reflex camera, LED-based light sources, and filters to allow the analysis of the self-fluorescence signal. The proposed solution aspires to improve the standardization of monitoring plans through non-destructive fine-scale accurate data collection for image analysis and multi-temporal comparisons, providing challenging stepping-stones for habitat-forming anthozoan management and restoration activities. Initial results of tests carried out in controlled conditions are shown. The photogrammetric approach resulted in 3D reconstructions that allow the monitoring of deformations at millimetre scale. The fluorimetry methodology allowed to obtain high-resolution images with great repeatability, which enabled the identification of stressful status even in absence of geometric deformations. The proposed approaches and obtained results are discussed, together with potential issues related to their implementation in a real-world context adopting remotely operative vehicles.

2022 - UAV Photogrammetry and GIS Interpretations of Extended Archaeological Contexts: The Case of Tacuil in the Calchaquí Area (Argentina) [Articolo su rivista]
Orsini, Carolina; Benozzi, Elisa; Williams, Veronica; Rossi, Paolo; Mancini, Francesco
abstract

The scope and scientific purpose of this paper focuses on multiscale (aerial and terrestrial) photogrammetry as a support to investigations and interpretations in a multi-component archaeological site located in the Argentinian Cordillera (Calchaquí, Salta), known as Tacuil. Due to its scarce accessibility, as well as long-term problems associated with the interpretation of the visibility of this type of settlement, the use of aerial surveying was combined with the reconstruction of structures and complex soil morphologies by resorting to modern photogrammetric approaches (3D models and orthophotos). This dataset was complemented by a terrestrial survey to obtain extremely high resolution and detailed representations of archaeological features that were integrated in a GIS database. The outcome of photogrammetric surveying was fundamental in supporting the debate on the functionality of the site and his integration in a complex, socially constructed, ancient landscape. Finally, the present paper introduces the first complete map of Tacuil.

2021 - Needs and gaps in optical underwater technologies and methods for the investigation of marine animal forest 3D-structural complexity [Articolo su rivista]
Rossi, Paolo; Ponti, Massimo; Righi, Sara; Castagnetti, Cristina; Simonini, Roberto; Mancini, Francesco; Agrafiotis, Panagiotis; Bassani, Leonardo; Bruno, Fabio; Cerrano, Carlo; Cignoni, Paolo; Corsini, Massimiliano; Drap, Pierre; Dubbini, Marco; Garrabou, Joaquim; Gori, Andrea; Gracias, Nuno; Ledoux, Jean-Baptiste; Linares, Cristina; Pulido Mantas, Torcuato; Menna, Fabio; Nocerino, Erica; Palma, Marco; Pavoni, Gaia; Ridolfi, Alessandro; Rossi, Sergio; Skarlatos, Dimitrios; Treibitz, Tali; Turicchia, Eva; Yuval, Matan; Capra, Alessandro
abstract

Marine animal forests are benthic communities dominated by sessile suspension feeders (such as sponges, corals, and bivalves) able to generate three-dimensional (3D) frameworks with high structural complexity. The biodiversity and functioning of marine animal forests are strictly related to their 3D complexity. The present paper aims at providing new perspectives in underwater optical surveys. Starting from the current gaps in data collection and analysis that critically limit the study and conservation of marine animal forests, we discuss the main technological and methodological needs for the investigation of their 3D structural complexity at different spatial and temporal scales. Despite recent technological advances, it seems that several issues in data acquisition and processing need to be solved, to properly map the different benthic habitats in which marine animal forests are present, their health status and to measure structural complexity. Proper precision and accuracy should be chosen and assured in relation to the biological and ecological processes investigated. Besides, standardized methods and protocols are strictly necessary to meet the FAIR (findability, accessibility, interoperability, and reusability) data principles for the stewardship of habitat mapping and biodiversity, biomass, and growth data.

2020 - Coral Reef Monitoring by Scuba Divers Using Underwater Photogrammetry and Geodetic Surveying [Articolo su rivista]
Nocerino, Erica; Menna, Fabio; Gruen, Armin; Troyer, Matthias; Capra, Alessandro; Castagnetti, Cristina; Rossi, Paolo; Brooks, Andrew J.; Schmitt, Russell J.; Holbrook, Sally J.
abstract

Underwater photogrammetry is increasingly being used by marine ecologists because of its ability to produce accurate, spatially detailed, non-destructive measurements of benthic communities, coupled with affordability and ease of use. However, independent quality control, rigorous imaging system set-up, optimal geometry design and a strict modeling of the imaging process are essential to achieving a high degree of measurable accuracy and resolution. If a proper photogrammetric approach that enables the formal description of the propagation of measurement error and modeling uncertainties is not undertaken, statements regarding the statistical significance of the results are limited. In this paper, we tackle these critical topics, based on the experience gained in the Moorea Island Digital Ecosystem Avatar (IDEA) project, where we have developed a rigorous underwater photogrammetric pipeline for coral reef monitoring and change detection. Here, we discuss the need for a permanent, underwater geodetic network, which serves to define a temporally stable reference datum and a check for the time series of photogrammetrically derived three-dimensional (3D) models of the reef structure. We present a methodology to evaluate the suitability of several underwater camera systems for photogrammetric and multi-temporal monitoring purposes and stress the importance of camera network geometry to minimize the deformations of photogrammetrically derived 3D reef models. Finally, we incorporate the measurement and modeling uncertainties of the full photogrammetric process into a simple and flexible framework for detecting statistically significant changes among a time series of models.

2020 - Detecting change in coral reef 3D structure using underwater photogrammetry: critical issues and performance metrics [Articolo su rivista]
Rossi, P.; Castagnetti, C.; Capra, A.; Brooks, A. J.; Mancini, F.
abstract

This paper presents a multi-temporal underwater photogrammetric survey of a reef patch located in Moorea, French Polynesia, designed to detect a coral growth of 10–15 mm/year. Structure-from-Motion photogrammetry and underwater imagery allows the three-dimensional quantification of reef structural complexity and ecologically relevant characteristics at the patch scale. A high degree of accuracy and fine resolution are required in order to guarantee the repeatability of surveys over time within the same reference system, meaning a proper geodetic network and acquisition scheme are mandatory. Measuring tools and reference points were properly designed in order to constrain the photogrammetric reconstruction. The network adjustment, performed with distance and height difference observations, provided an average accuracy of ± 1.2 mm and ± 2.9 mm in the horizontal and vertical components, respectively. The final accuracies of photogrammetric reconstructions are on the order of 1 cm and few millimeters for the 2017 and 2018 monitoring campaigns, respectively. This results in realized errors in the comparison of about ± 1 cm. Coordinate variations larger than this magnitude can be reasonably interpreted as coral growth or dissolution. The direct comparison of the two subsequent point clouds is effective in order to evaluate trends in growth and perform morphometric analyses. For highly accurate quantitative assessment of local changes, an expert operator can create and analyze specific 2D profiles that are easily produced from the point clouds.

2020 - Underwater Photogrammetry for Change Detection [Relazione in Atti di Convegno]
Capra, Alessandro; Castagnetti, Cristina; Mancini, Francesco; Rossi, Paolo
abstract

2019 - A new methodological approach to assess the stability of discontinuous rocky cliffs using in-situ surveys supported by UAV-based techniques and 3D finite element model: a case study [Articolo su rivista]
Fazio, N. L.; Perrotti, M.; Andriani, G. F.; Mancini, F.; Rossi, P.; Castagnetti, C.; Lollino, P
abstract

This paper aims to present a new methodological approach for the stability assessment of coastal cliffs constituted of discontinuous rock masses. The method entails in situ specific geostructural and geomechanical surveys, three-dimensional UAV-based Photogrammetric structural models, laboratory geotechnical tests and, two- and three-dimensional finite element analysis (FEM). The application of the method to a case study is then presented and discussed; it regards a 600 m long sea rocky cliff located at Sant'Andrea (Melendugno, South of Apulia, SE Italy) and faced to the southern Adriatic Sea. Here the cliff is made up of an about 15 m-thick sequence of laminate calcisiltites alternate with bioturbated calcarenites belonging to the Uggiano la Chiesa Fm. (Middle-Upper Pliocene). The structural discontinuities detected with photogrammetry techniques were compared and validated with those derived from conventional in situ survey methods. Later on, the paper discusses assumptions and results of two- and three-dimensional finite element models developed to investigate the potential failure mechanisms of the sea cliff accounting for pre-existing weak planes or discontinuities with unfavourable orientation. The failure mechanisms obtained by both FEM analysis agree well with those typically observed in the study area.

2019 - COMPARISON of DIVER-OPERATED UNDERWATER PHOTOGRAMMETRIC SYSTEMS for CORAL REEF MONITORING [Relazione in Atti di Convegno]
Nocerino, E; Neyer, F; Gruen, A; Troyer, M; Menna, F; Brooks, A; Capra, A; Castagnetti, C; Rossi, Paolo
abstract

Underwater photogrammetry is a well-established technique for measuring and modelling the subaquatic environment in fields ranging from archaeology to marine ecology. While for simple tasks the acquisition and processing of images have become straightforward, applications requiring relative accuracy better then 1:1000 are still considered challenging. This study focuses on the metric evaluation of different off-the-shelf camera systems for making high resolution and high accuracy measurements of coral reefs monitoring through time, where the variations to be measured are in the range of a few centimeters per year. High quality and low-cost systems (reflex and mirrorless vs action cameras, i.e. GoPro) with multiple lenses (prime and zoom), different fields of views (from fisheye to moderate wide angle), pressure housing materials and lens ports (dome and flat) are compared. Tests are repeated at different camera to object distances to investigate distance dependent induced errors and assess the accuracy of the photogrammetrically derived models. An extensive statistical analysis of the different systems is performed and comparisons against reference control point measured through a high precision underwater geodetic network are reported.

2019 - High accuracy underwater photogrammetric surveying [Relazione in Atti di Convegno]
Capra, A.; Castagnetti, C.; Dubbini, M.; Gruen, A.; Guo, T.; Mancini, F.; Neyer, F.; Rossi, P.; Troyer, M.
abstract

The evolution of underwater photogrammetry allows to realize 3D models of submerged object and structures throughout the use of rapid and efficient procedures either in terms of data acquisition and data processing. These procedures are based on solutions that are applied using natural control points, signalized markers and tie points; the most common algorithms are based on Structure from Motion (SfM) approach. The limit of these applications is sometimes due to the final accuracy, especially when the goal is a centimeter level of accuracy. This accuracy should be necessary when dealing with a survey devoted to deformation control purposes. An example is the underwater photogrammetry for the determination of coral growth; it is effectively a movement or a deformation detection issue where the geometric change is almost at centimeter or few centimeters accuracy level. When dealing with deformation control applications, a geodetic network is essential to realize a stable and unambiguous reference frame through the accurate and permanent installation of Ground Control Points (GCPs). Such a network, indeed, permits a robust reference frame for the georeferencing of images blocks in the different époques of data acquisition. Therefore, the comparison among subsequent photogrammetric restitutions is based on homogeneous 3D models that have been oriented in the same absolute reference system. The photogrammetric survey is based on a methodological approach especially adapted to underwater biometry (like coral growth determination) and to underwater archaeology. The approach is suitable both for modeling objects of relatively reduced dimensions and for structures with a length of ten meters or more, such as coral barriers, wrecks and long walls. The paper describes underwater photogrammetric surveys on sites at different extensions, the geodetic GCPs reference network installation and measurements (distance and elevation difference observations) as well as preliminary results of the network adjustment. A brief description of image acquisition at a different scales and the resulting 3D model of first campaign are also shown.

2019 - POTENZIALITÀ E PROBLEMATICHE NELL’UTILIZZO DELLA FOTOGRAMMETRIA SUBACQUEA PER LA MISURA DELL’ACCRESCIMENTO DI COLONIE CORALLIGENE [EVALUATION OF UNDERWATER PHOTOGRAMMETRY’ PERFORMANCES IN THE ASSESSMENT OF CORAL REEF 3D CHANGES] [Articolo su rivista]
Rossi, P.; Castagnetti, C.; Capra, A.; Brooks, A. J.; Mancini, F.
abstract

This paper presents a multi-temporal underwater photogrammetric survey of a reef patch located in Moorea Island (French Polynesia) to detect a coral growth at a required level of accuracy of 10-15 mmyears. An approach based on processing of underwater imagery by the well-known Structure from Motion method and ground control points derived from the adjustment of underwater topographic measurements allowed the three-dimensional quantification of ecological characteristic at patch scale and an assessment of the reef growth and its structural complexity. To guarantee the repeatability of surveys over time at required level of accuracy and spatial resolution, the paper introduces issues related to reference frame, network adjustment and design of photogrammetric surveying. Measuring tools and reference points were properly designed and presented by the authors. The network adjustment performed after measuring distances and height differences, provided an average precision of 1.2 mm and 2.9 mm in the horizontal and vertical component respectively. The final positional precision of photogrammetric reconstructions was in the order of 1 centimeter and few millimeters for 2017 and 2018 monitoring campaigns respectively. Then, the accuracy of the comparison resulted of about 1 cm which represents a factor to be considered in the successive interpretations of coral growth or dissolution phenomena. The direct comparison of the two subsequent point clouds is effective in the evaluation of growth rates and in the successive morphometric analyses. For highly accurate quantitative assessment of local changes, an expert operator can create and analyze specific 2D profiles that easily come from the point clouds.

2019 - Photogrammetry and Remote Sensing for the identification and characterization of trees in urban areas [Articolo su rivista]
Mueed Choudhury, M. A.; Costanzini, S.; Despini, F.; Rossi, P.; Galli, A.; Marcheggiani, E.; Teggi, S.
abstract

For the last few decades, there have been a lot of studies recognising the significant roles of the urban trees as a high-quality carbon sink. This work is a preliminary study about how remote sensing and photogrammetry could be useful tools to identify urban trees for the purpose of Carbon Storage (CS) computation in urban areas. Our first study area is a typical urban park located in Sassuolo, a municipality in the northern part of Italy in the so-called "Pianura Padana". We measured the tree Height (H) and the Diameter at Breast Height (DBH), required for the calibration of the CS, based on the tree allometry during the field data collection along with the constructing a 3D model through the photogrammetric approach. A high-resolution WorldView (WV) 3 satellite image of the same area, was classified using an object-oriented approach to count the number of trees varied with different species. This preliminary study will enhance the possibilities of the application of these approaches in case of the larger urban areas to ascertain the accuracy of the tree CS calibration.

2018 - 3D Reconstruction of rock paintings: a cost-effective approach based on modern photogrammetry for rapidly mapping archaeological findings [Relazione in Atti di Convegno]
Castagnetti, C; Rossi, P; Capra, A
abstract

The work describes a cost-effective methodology for the creation of 3D virtual models with both metric and photo-realistic content developed for archaeologists who need to rapidly map new findings during their field prospections. The potential of modern photogrammetry approach, based on Structure from Motion (SfM) and dense image matching algorithms, coupled with the use of low-cost cameras is evaluated for the creation of 3D models and orthophotos of rock paintings. The case study is located in Brealito valley, in the Calchaqui basin of the Province of Salta, Argentina. In these wide areas, actually known for the naturalistic value, a huge amount of archeological remains was found and surveyed for the first time in August 2013 within a research project funded by the Italian Ministry of Foreign Affairs. A methodological approach to record the findings in a cost-effective and reliable way is defined, acquisitions are performed with common use instruments such as digital cameras (off-the-shelf and single lens reflex - SLR) and measuring tapes. The novelty of the work lies in defining, experiencing and transferring to operators a simple methodology for digitizing and mapping the archeological heritage in order to provide 2D orthophotos and 3D models. Such methodology allows anyone, archaeologists or unprofessional personnel, to be trained and easily perform a survey in order to document, survey and study the investigated site.

2017 - An Integrated Procedure to Assess the Stability of Coastal Rocky Cliffs: From UAV Close-Range Photogrammetry to Geomechanical Finite Element Modeling [Articolo su rivista]
Mancini, Francesco; Castagnetti, Cristina; Rossi, Paolo; Dubbini, Marco; Fazio, Nunzio Luciano; Perrotti, Michele; Lollino, Piernicola
abstract

The present paper explores the combination of unmanned aerial vehicle (UAV) photogrammetry and three-dimensional geomechanical modeling in the investigation of instability processes of long sectors of coastal rocky cliffs. The need of a reliable and detailed reconstruction of the geometry of the cliff surfaces, beside the geomechanical characterization of the rock materials, could represent a very challenging requirement for sub-vertical coastal cliffs overlooking the sea. Very often, no information could be acquired by alternative surveying methodologies, due to the absence of vantage points, and the fieldwork could pose a risk for personnel. The case study is represented by a 600 m long sea cliff located at Sant’Andrea (Melendugno, Apulia, Italy). The cliff is characterized by a very complex geometrical setting, with a suggestive alternation of 10 to 20 m high vertical walls, with frequent caves, arches and rock-stacks. Initially, the rocky cliff surface was reconstructed at very fine spatial resolution from the combination of nadir and oblique images acquired by unmanned aerial vehicles. Successively, a limited area has been selected for further investigation. In particular, data refinement/decimation procedure has been assessed to find a convenient three-dimensional model to be used in the finite element geomechanical modeling without loss of information on the surface complexity. Finally, to test integrated procedure, the potential modes of failure of such sector of the investigated cliff were achieved. Results indicate that the most likely failure mechanism along the sea cliff examined is represented by the possible propagation of shear fractures or tensile failures along concave cliff portions or over-hanging due to previous collapses or erosion of the underlying rock volumes. The proposed approach to the investigation of coastal cliff stability has proven to be a possible and flexible tool in the rapid and highly-automated investigation of hazards to slope failure in coastal areas.

2017 - Combining nadir and oblique UAV imagery to reconstruct quarry topography: methodology and feasibility analysis [Articolo su rivista]
Rossi, Paolo; Mancini, Francesco; Dubbini, Marco; Mazzone, Francesco; Capra, Alessandro
abstract

The feasibility of unmanned-aerial-vehicle-based photogrammetry was assessed for the reconstruction of high-resolution topography and geomorphic features of quarries by nadir and off-nadir imagery. The test site was a quarry located in the rural area of Turi (Bari, southern Italy). Two processing scenarios were created. Nadir images were initially used, and images acquired with off-nadir angles were added. An accurate set of ground control points (GCPs) were surveyed for both georeferencing purposes and validation processes. In the reconstruction of the surfaces, an accuracy of a few centimeters was achieved in the final positioning of point clouds representing the main geometries of quarry environment. However, greatest differences were found along the edges or the lines characterized by sudden slope changes. To better understand such results, some characteristic quarry shapes depicted by both the scenarios were compared to those surveyed by a total station used as an independent benchmark technique. It allowed to define the benefits introduced by the joint use of nadir and oblique images in the delineation of quarry shapes, surface discontinuities and better descriptions of sub-vertical walls. Beside the evaluation of benefits introduced by use of oblique cameras, the effectiveness of the proposed methodology was also discussed with alternative technologies. Unmanned aerial platforms represent an effective solution, with the need for few accurate GCPs.

2016 - Achievement of the “benchmark” session - on the use of UAV images for 3D reconstruction: a joint experience among users” (held during the 61th SIFET meeting, Lecce, Italy, june 8-10, 2016) [Articolo su rivista]
Mancini, Francesco; Castagnetti, Cristina; Rossi, Paolo; Altri, Autori
abstract

This paper summarize the achievements of an experimental meeting session held within the 61th SIFET national meeting (Lecce, Italy, 6-10 June 2016). The session named “benchmark” introduced results achieved by users in the processing of a shared dataset, composed of images acquired from unmanned aerial vehicle (UAV), to reconstruct the three-dimensional properties of cultural heritage. Data, results provided by authors and validation strategies of outcomes from the photogrammetric processing of UAV images highlighted different level of spatial accuracy by the products. Despite the good level of automation introduced by the structure from motion approach to data processing, the users detected differences at cm-level in the accuracy of results after the use of available software. ITA: Il lavoro riassume i risultati ottenuti da diversi partecipanti alla sessione “benchmark” - uso di immagini UAV per la ricostruzione 3D: esperienze condivise tra utenti, svoltasi nell’ambito del 61° convegno nazionale SIFET (Lecce 8-10 giugno 2016). L’iniziativa ha previsto l’elaborazione di un dataset comune, rappresentato da immagini acquisite tramite aeromobile a pilotaggio remoto, ai fini della ricostruzione tridimensionale di ambienti di pregio storico e culturale. Tra gli obiettivi principali vi era quello di confrontare i diversi approcci seguiti dai partecipanti nell’elaborazione dei dati, mettendo in luce le diverse potenzialità dei software disponibili, le possibili strategie relative all’uso dei punti di controllo e il livello di accuratezza raggiunto. Nonostante l’utilizzo di procedure consolidate nell’analisi dei dati, i risultati riportati dagli utenti evidenziano significative differenze nei livelli di accuratezza, verificabili dopo il confronto con i punti di controllo e con la nuvola di punti ottenuta con scansione laser terrestre.

2016 - POTENTIALITY OF THE NEW WEARABLE SYSTEMS FOR 3D SCANNING AN EXPERIMENTATION OF PEGASUS BACKPACK BY LEICAGEOSYSTEMS PRESSO AT THE DUCAL PALACE OF MODENA [Articolo su rivista]
Castagnetti, Cristina; Mancini, Francesco; Rivola, Riccardo; Rossi, Paolo; Oppici, Simone; Albano, Valentina; Fiorentini, Marco
abstract

The terrestrial laser scanning is a well established technology for a wide range of applications. Recently the development of wearable systems based on multiple profilers and cameras opens to new challenging field of applications. The potentialities of such systems in terms of accuracy, productivity, completeness of the final dataset has been tested and described in the paper. The case study is provided by the Military Academy of Modena where an expeditious survey was carried out both in internal and external environments with the objective of evaluating the performance of the Leica Pegasus Backpack, a wearable system, in comparison with the Leica ScanStation C10, a traditional terrestrial laser scanner in static position. The field test allows to highlight the most suitable applications for these wearable systems.

2009 - Reverse shoulder prosthesis as revision surgery after fractures of the proximal humerus, treated initially by internal fixation or hemiarthroplasty [Articolo su rivista]
Lollino, Nicola; Paladini, Paolo; Campi, Fabrizio; Merolla, Giovanni; Rossi, Paolo; Porcellini, Giuseppe
abstract

Complex (3-4 fragments) fractures of the proximal humerus often have a bad outcome, whatever treatment is performed. When revision surgery is required, reverse shoulder prosthesis can improve function and reduce pain in these patients. We analysed whether the choice of the first treatment (hemiarthroplasty vs. reduction and fixation) can influence the outcome of revision surgery. Our data demonstrate that results are not significantly dependent on the choice of the first implant, even though there is a tendency for patients with previous hemiarthroplasty to have a worse outcome.

2008 - Informed consent in shoulder surgery [Articolo su rivista]
Porcellini, Giuseppe; Campi, Fabrizio; Paladini, Paolo; Rossi, Paolo; Lollino, Nicola
abstract

Informed consent is an essential tool for diagnosis and therapy in medicine, and is of fundamental importance in surgery, where it underpins the operation itself. Its origins can be traced back to US forensic medicine but is now incorporated into the Italian legal system, with different consequences depending on the context in which it is applied. This article describes our experiences in shoulder surgery, with suitable references to legislation and analysis of the literature studies in this area.