UAV photogrammetric survey and image-Based elaborations for an Industrial Plant.

The proposed application of the HBIM methodology for digitising a productive-industrial structure is based on the integration of data from different sources. An aerial photogrammetric survey (Unmanned Aerial Vehicle - UAV) was considered the most appropriate technique for the case. Therefore, a Scan-to-BIM modelling was carried out, keeping in mind a subsequent texturisation of the smart objects employing the photogrammetric images obtained from the UAV survey. Currently, applying the BIM methodology to the built environment is still a challenge; indeed, three-dimensional modelling based on survey point clouds is not automatic. Any BIM software is designed for new constructions, whereas the existing Heritage is characterised by unique and distinctive shapes, where each element has a specific and variable inclination, shape and thickness; therefore, it is necessary to adapt the available tools. Creating intelligent parametric objects capable of representing the unique and singular shapes and geometries of historic architecture is a significant challenge of HBIM modelling. A workflow for the acquisition, processing and management of the survey data and the consequent modelling in a BIM environment of a disused industrial plant previously used as a tobacco factory was formalised. The aim was, therefore, to develop a model that is as close as possible to the real one and, at the same time, still keeps the informative aspects in order to promote the conservation and possible refurbishment of the cultural heritage through the use of photorealistic visualisation tools in real-time. The results confirm the proposed strategy hypotheses and seem to lead to promising future developments

Vehículos aéreos no tripulados para el levantamiento y monitoreo de áreas arqueológicas

2016 - 2017The research focused on the analysis of the deviation that an aerofotogrammetric survey can produce with respect to the classic topographic surveys, by total station, GPS (Global Positioning System) or TLS (Terrestrial Laser Scanner), instruments with significantly higher sensitivity than the airborne system, and therefore affected by minor uncertainties. In the various applications, using topographic measurements from different systems and using the so-called GCP (Ground Control Point), the metric deviations between the geo-referenced photogrammetric model and the topographic support were calculated, evaluating the system’s metric potential in different configurations. Moreover, by a script, the reprojection errors were measured for each point of the cloud generated by the entire photogrammetric process; from statistical analysis of the reprojection error in the various case studies, the modalities for which the aerofotogrammetric survey has the smallest deviations have been evaluated. The elaborated case studies come essentially within the archaeological field, in which, in close contact with the various Sovraintendenze, the possible elaborations to be returned for an initial computerization of the survey were analyzed. The set of works produced and delivered to the various Sovraintendenze, represents the starting point for the conservation and preservation of the archaeological heritage, from which to obtain information for different areas of interest (degradation assessment, calculation of subsidence and / or deformations, etc…). The comparison with the classical topography is necessary for a metric comparison of the 3D model, from which all the elaborates will be derived (orthophotos, sections, level curves, etc.)...[edited by Author]XXX cicl

Técnicas y metodologías para la documentación y la supervisión del patrimonio natural

The study for any type of intervention on cultural heritage, provides a preliminary stage of documentation of the asset on which to intervene, whether it is an asset belonging to the so-called historical heritage, or an asset of landscape - natural interest. The work presents an integrated 3D survey methodology for the restitution of three-dimensional information, georeferenced and with centimetre accuracy, for the restitution of elaborate metrics of a natural pool in south-eastern Italy, in the municipality of Marina Serre. The natural pool surveyed presents a series of critical points, such as vaulted passages and areas to be surveyed in the sea; to obtain a complete 3D model of the object of study the instruments used were a Terrestrial Laser Scanner (TLS), mainly used for the acquisition of the cavities present in the site, and an aerial photogrammetry from unmanned aerial Vehicle (UAV), necessary for the digitalization of the coastal zone where the pool is present. The data have been merged, in a single point cloud model extremely detailed, to then derive all the necessary metric information from this. The results obtained show that the methodology illustrated in the study can be replicated for the documentation and/or monitoring of any object of high environmental interest, without vegetation.El estudio para cualquier tipo de intervención sobre el patrimonio cultural prevé una etapa preliminar de documentación del bien sobre el que se va a intervenir, ya sea un bien perteneciente al llamado patrimonio histórico o un bien de interés natural - del paisaje. El trabajo presenta una metodología integrada de levantamiento tridimensional para la restitución de información tridimensional georreferenciada y con precisión de centímetros, con el fin de contar con una restitución de métricas elaboradas para una piscina natural en el sudeste de Italia, en el municipio de Marina Serre. La piscina natural estudiada presenta una serie de puntos críticos, como zonas abovedadas y zonas a estudiar en el mar; para obtener un modelo tridimensional completo del objeto de estudio se utilizaron instrumentos como un escáner láser terrestre (TLS), utilizado principalmente para la adquisición de las cuevas presentes en el lugar y una aerofotogrametría desde un vehículo aéreo no tripulado, necesaria para la digitalización de la zona costera donde está presente la piscina. Los datos han sido fusionados, en un modelo único de nubes de puntos extremadamente detallado, para luego derivar toda la información métrica necesaria a partir de esto. Los resultados obtenidos muestran que la metodología ilustrada en el estudio puede ser replicada para la documentación y/o monitoreo de cualquier objeto de alto interés ambiental, sin vegetación

I droni per il rilievo di siti archeologici e la documentazione del paesaggio

Il principale spunto di riflessione che vuole proporre la monografica di Marco Limongiello (autore dei capitoli) e Salvatore Barba (autore della prefazione, postfazione e dell’inquadramento e contestualizzazione degli studi nello stato generale dell’arte dei droni per la documentazione dell’architettura), nonché l’approccio più innovativo, è la proposta di una metodologia generale e per il calcolo del grado di accuratezza finale di un rilievo, fin troppo spesso non tenuto in conto dai non esperti del settore

Image–Based Modelling Restitution: Pipeline for Accuracy Optimisation

The paper presents an innovative approach to support survey methods by applying AI algorithms to improve the accuracy of point clouds generated from UAV imagery. The work analyses different photogrammetric accuracy parameters in a first step, such as reprojection error and the intersection angle between homologous rays, verifying that a single parameter is enough to evaluate the accuracy of the photogrammetric restitution. Therefore, some of the calculated parameters were analysed through a Self–Organizing Map (SOM) to reach a compromise between the value of the variables analysed and the noise reduction associated with the 3D model definition. In the case study, it has been observed that the parameter that most influences the noise in the photogrammetric point clouds is the intersection angle

Correlation among Earthwork and Cropmark Anomalies within Archaeological Landscape Investigation by Using LiDAR and Multispectral Technologies from UAV

This project aimed to systematically investigate the archaeological remains of the imperial Domitian villa in Sabaudia (Italy), using different three-dimensional survey techniques. Particular attention in the research was paid to the identification and documentation of traces that buried structures left on the surface occupied by the villa, which extended for 46 hectares, an area that was fully covered with structures. Since a dense pine forest was planted during the 1940s and is currently covering the site, this contribution investigates particularly the correlation among the presence of cropmarks, identifiable with the processing of multispectral maps and vegetation indices from RGB images, and earthwork anomalies identified in a Digital Terrain Model (DTM) built, by utilizing a light detection and ranging (LiDAR) flight from an Unmanned Aerial Vehicle (UAV). The study demonstrates how the use of vegetation maps—calculated starting from RGB and multispectral aerial photos—can provide a more expeditious preliminary analysis on the position and extension of areas characterized by the presence of buried structures, but also that, in order to investigate in-depth a context in similar conditions, the most effective approach remains the one based on LiDAR technology. The integration between the two techniques may prove fruitful in limiting the extension of the areas to be investigated with terrestrial survey techniques

Image-Based and Range-Based Dataset Integration for an Efficient 3D Representation

Digital technologies provided an opportunity for innovation and development in the graphic repre- sentation field during the pandemic when scientific communication was forced into digital commu- nication channels. The digital survey with the image-based and range-based techniques integration allows optimizing 3D measurements and the related technical representations. This study presents the analysis of an innovative pipeline to integrate the Terrestrial Laser Scanner (TLS) dataset directly into the photo- grammetric pipeline within a single software environment. The main objective was to test different procedures for the alignment and integration of point clouds from active (TLS) and passive (clo- se-range photogrammetry) sensors and provide a first metric evaluation. In particular, three methods were analyzed: scale and roto-translation with Ground Control Points through the photogrammetric self-calibration bundle adjustment; integration of the spherical panoramas by the single laser stations into the photogrammetric workflow; Python script to align the photogram- metric dense cloud in the TLS reference system through an Iterative Closest Point (ICP) procedure. The study presents the first results applied to a small architectural scale case study: the Mulino del Cantone, a watermill along the Lambro river in the Park of Monza (MB). The mixed approach opens new opportunities to achieve an efficient 3D survey and a complete graphic representatio

Uno strumento UAV sperimentale per una metodologia sempre più consolidata: il caso di Via di Nocera a Pompei (Una herramienta VANT experimental para una metodología cada vez más consolidada: el caso de Via di Nocera en Pompeya)

Il rilevamento aereo nel campo dell’architettura e dell’archeologia sta riscuotendo sempre maggior interesse, soprattutto a seguito dello sviluppo tecnologico dei VANT (vehículo aéreo no tripulado), più famosi nella terminologia inglese UAV (Unmanned Aereal Vehicles). Negli ultimi anni, infatti, questi mezzi hanno migliorato notevolmente le loro caratteristiche, come il tempo di volo, la stabilità e il payload. Parallelamente, abbiamo assistito alla miniaturizzazione del sensore che, non a discapito della qualità, ha aperto nuove frontiere per il rilievo fotogrammetrico fino a pochi anni fa quasi inimmaginabili. A questo sviluppo ha contribuito anche il progresso dei software di fotogrammetria digitale, con l’introduzione sempre più spinta di nuovi algoritmi di calcolo – Structure from Motion –, per la restituzione di orto-immagini ad alta definizione, spesso requisito necessario per la documentazione e la conservazione del patrimonio archeologico. Proprio in questo filone di ricerca si colloca il caso studio, qui presentato a scopo principalmente divulgativo, del rilievo fotogrammetrico da mezzo UAV di Via di Nocera, nell’area archeologica degli scavi di Pompei, patrimonio Unesco dal lontano 1997. Dal processamento delle immagini, a valle di un’accurata campagna topografica con la battuta dei necessari Ground Control Point (GCP), è stata restituita un’orto-immagine ad alta risoluzione e georeferenziata. L’analisi metrica rispetto i GCP ha riscontrato errori puntuali inferiori ai 2 cm, validando metricamente le rappresentazioni per elaborati in scala 1:50 (o anche più grande), essenziali per una dettagliata documentazione del basolato e permettendone, così, una nuova lettura anche del relativo stato di degrado.El levamiento aéreo en el campo de la arquitectura y arqueología, está demostrando siempre mayor interés, principalmente luego del desarrollo tecnológico de los VANT (Vehículo aéreo no tripulado) o más conocido en su término en inglés UAV (Unmanned Aereal Vehicles). En los últimos años, en efecto, estos medios han mejorado notablemente sus características, ya sea, el tiempo y la estabilidad del vuelo, y el payload. Al mismo tiempo, hemos sido testigos del desarrollo tecnológico de los sensores pasivos, capaces en pocos años, de la miniaturización, que abre nuevas fronteras en el levantamiento fotogramétrico, situación que pocos años atrás era inimaginable. En este desarrollo, ha contribuido también el progreso de los softwares de fotogrametría digital, con la introducción de nuevos algoritmos de cálculo – Structure from Motion –, para la restitución de orto-fotos de alta definición, muchas veces requisito esencial para la documentación y la conservación del patrimonio arqueológico. Precisamente en este ámbito de investigación se localiza el caso de estudio, aquí presentado con un objetivo principalmente divulgativo, del levamiento fotogramétrico por medio de VANT de Via di Nocera, en el área arqueológica de Pompeya, patrimonio de la Unesco desde el lejano 1997. Desde el procesamiento de las imágenes, capturadas a partir de una precisa campaña de recolección y con la utilización de los necesarios Ground Control Point (GCP), ha sido restituida una orto-imagen de alta resolución y geo-referenciada. El análisis métrico respecto los GCP ha evidenciado errores puntuales inferiores a los 2 cm, validando métricamente la representación para piezas graficas en escala 1:50 (o incluso más grande), esencial para una detallada documentación del pavimento y permitiendo también, de esta manera, una nueva lectura del relativo estado de degrado

FIELD WORK MONITORING AND HERITAGE DOCUMENTATION FOR THE CONSERVATION PROJECT. THE “FORO EMILIANO” IN TERRACINA (ITALY)

The area of the “Foro Emiliano”, the current “Piazza del Municipio” in the coastal town of Terracina in southern Latium, consists of an articulated group of building belonging to different historical moments. On the roman pavement of the forensic square stand out: a Roman theatre, the urban cathedral, medieval houses, a roman temple and recent buildings dating from the first half of the 20th century. Thanks to recent funding the “Soprintendenza Archeologia, Belle Arti e Paesaggio per le province di Frosinone, Latina e Rieti” has undertaken the demolition of some modern houses insisting on the theatre’s porticus post scaenam and began an excavation of the entirely preserved cavea of the Roman theatre building. These interventions of urban archaeology were taken as an opportunity to plan an impressive 3D survey of the historic center, aiming: on one side at monitoring demolition and excavation work, offering a cartographic base for valorization projects, and on the other at the investigation of a vast monumental area. This paper analyses in detail the phases of integration, alignment, filtering and post processing of the acquired data, showing with evidence how the integration of active and passive sensors is the best approach in similar scenario