1,721,007 research outputs found
Fior da fiore: il commento scolastico e la creazione del 'canone' della letteratura italiana
No full textUn approccio chemiometrico per lo studio della tipologia di fibule ad arco ritorto nel villanoviano bolognese
No full textUn esempio d’uso dell’Analisi delle Componenti Principali (PCA) per la verifica tipologica: le fibule ad arco ritorto della necropoli villanoviana di San Vitale (Bologna)
No full textLa statistica multivariata in archeologia: studio della cronologia relativa e di una classe di fibule della necropoli villanoviana di San Vitale a Bologna
No full textGeneration of a multi-scale historic BIM-GIS with digital recording tools and geospatial information
Full text linkThis paper discusses the creation of an integrated historic BIM-GIS for the complex of San Pietro al Monte, an important Romanesque monument in Civate (Italy) inscribed in the UNESCO tentative list with other seven medieval Benedictine settlements. The reason behind the choice of an integrated H-BIM-GIS solution is motivated by the large extension of the considered area (about 30 km2) and the need for multi-scale digital information integrated into a 3D parametric environment. The model includes geospatial information at a territorial scale and in situ digital data capturing the complex at a higher level of detail. The work aims at exploring the pros and cons of a novel parametric 3D environment able to integrate both BIM and GIS data, methods, and processing tools in the case of historic buildings and sites
3D MODELING WITH 5K 360° VIDEOS
Full text linkVideo acquisition with 360° (spherical) cameras is becoming increasingly popular for the opportunity to capture the entire scene around the user in a relatively short time. The method can also be attractive for photogrammetric applications. As the overlap between consecutive frames is undoubtedly guaranteed, 3D models can be generated with an automated processing workflow. The paper illustrates the results achieved with 5k 360° videos captured with different Insta360 cameras. As the number of frames can become large, two complementary solutions are proposed to provide approximate initial exterior orientation parameters: The integration of the trajectory captured through GNSS, and the creation of an acquisition plan with a GIS-based application. The availability of approximated EO parameters provides a visibility map between the frames and reduces the computational cost during image matching. Experimental results demonstrate that such preliminary information is necessary for large datasets. Indeed, the photogrammetric processing of the entire dataset without the proposed preliminary EO parameters resulted in unreliable or incomplete orientation results
GNSS assisted photogrammetric reconstruction from combined 360° videos and uav images
Full text linkThis paper introduces an integrated approach utilizing ground data consists of videos captured with a 360° (spherical) camera and aerial data acquired with a UAV equipped with a RTK GNSS module to reconstruct a portion of a small-Town city center and/or a cultural heritage site. Previous research has demonstrated that image blocks oriented with RTK data on camera position can reach centimeter accuracies and can be efficiently used to reconstruct large areas and single monuments. However, some areas like porches, narrow passages and streets cannot be properly reconstructed from an aerial point of view. Conversely, ground-based 360° images offer detailed insights into the terrain and features that may be obscured from an aerial perspective. Integration of those two points of view can increase spatial resolution and coverage for 3D reconstruction. Indeed, the UAV captures large-scale features and topography, while ground-based 360° images focus on intricate details and ground-level characteristics. The possibility to exploit GNSS data acquired by UAV may also be used for GNSS-Assisted image orientation with the aim of reducing or even avoiding, in specific situations, the need for GCPs. The paper explores practical applications of such data integration in the cultural heritage domain demonstrating the efficacy of the integrated approach in scenarios with complex architectures and inaccessible areas
The use of terrestrial laser scanning techniques to evaluate industrial masonry chimney verticality
No full textThis paper presents a strategy to measure verticality deviations (i.e. inclination) of tall chimneys. The method uses laser scanning point clouds acquired around the chimney to estimate vertical deviations with millimeter-level precision. Horizontal slices derived from the point cloud allows us to inspect the geometry of the chimney at different heights. Two methods able to estimate the center at different levels are illustrated and discussed. A first solution is a manual approach that uses traditional CAD software, in which circle fitting is manually carried out through point cloud slices. The second method is instead automatic and provides not only center coordinates, but also statistics to evaluate metric quality. Two case studies are used to explain the procedures for the digital survey and the measurement of vertical deviations: The chimney in the old slaughterhouse of Piacenza (Italy), and the chimney in Leonardo Campus at Politecnico di Milano (Italy)
Visualization and Processing of Structural Monitoring Data Using Space-Time Cubes
No full textThis paper aims to analyze space-time cubes for visualizing and processing multi-temporal spatial monitoring data. The proposed case study is the Cathedral of Milan (Duomo di Milano), which has a set of monitoring time series spanning more than half a century. Differential vertical movements are periodically measured for the cathedral columns, constituting a continuous spatio-temporal dataset for structural health monitoring. More specifically, the space time pattern mining toolbox in ArcGIS Pro was used to (i) create a space-time cube and (ii) perform advanced analysis using the monitoring dataset, including time-series clustering and forecasting operations
360° IMAGE ORIENTATION AND RECONSTRUCTION WITH CAMERA POSITIONS CONSTRAINED BY GNSS MEASUREMENTS
Full text linkPhotogrammetric applications using 360° images are becoming more and more popular in different fields, such as cultural heritage documentation of narrow spaces; civil, architectural, and environmental projects like tunnel surveying; mapping of urban city centres, etc. The popularity of 360° photogrammetry relates to the high productivity of the acquisition phase, giving the opportunity to capture the entire scene around the user in a relatively short time. On the other hand, the photogrammetric workflow needs ground control points (GCPs), well distributed over the survey area, to georeference the produced 3D data. Placing, measuring on-field, and identifying GCP on images is time-consuming and sometimes even not feasible due to environmental conditions. While effective solutions exist for UAV-based projects, direct georeferencing and GNSS assisted photogrammetry is still not fully exploited for ground-based acquisitions. This paper aims at presenting a solution coupling 360° images and high-precision GNSS systems for direct georeferencing of outdoor projects without the need for manually measuring GCPs. Three different acquisition modes for 360° images and GNSS data are presented, and orientation results are compared with manually measured Check Points
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