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The big earthquake of August 24, 2016 and subsequent major shocks severely damaged many historic villages in Central Italy and dramatically showed the intrinsic vulnerability of the diffused archit...

In the wide framework of Scan-to-BIM 3D modelling procedures, the complexity of the architectural heritage and its components is evidencing a gap of best practices and specification in the HBIM-modeling and thus it is requiring important considerations about the modelling strategies and protocols between the requested level of detail (LOD), the expect accuracy and above all the actual use-oriented requirements. Several works are largely focusing on developing workflows for traditional static LiDAR scanning sensors. However, the chance to benefit from on-site faster data acquisition is needful at times, and procedures are directing toward rapid mapping 3D approaches, evolving from traditional static scanning toward MMS (Mobile Mapping Systems) based on SLAM technology (Simultaneous Localization and Mapping) algorithms implemented in portable devices. The potential of these solutions can contribute to increase a massive cost-effective documentation, and also in view of BIM-HBIM modelling generation, and this needs further researches. At the same time, the descriptive capabilities of this class of portable scanners do not reach the precision of the static solutions. Many time-cost balance evaluations towards an analysis of geometry, grade of generation (GOG) and details can be thus conducted. This paper presents a first comparison between TLS (Faro Focus 3D) and hand-held scanner Zeb Revo (by GeoSLAM) of the entire workflow (from raw data acquisition up to parametric modeling) focusing on the Bramante’s Canonica Court in the Basilica di Sant’Ambrogio. First, the two raw data are compared, considering geometric features (data density, precision, possibility to detect edges, details and accurate curvature). Then, some well-established modelling procedures developed for TLS data, as triangulation mesh and NURBS generation, are applied to MMS point cloud to identify their suitability. Different elements belonging to the architectural structure hierarchy are considered in a multi-scale perspective: the vaulted system of the porch, the columns and the arches of the porch with their different architectural elements.

The complex archaeological site documentation benefits for a long time now from the aerial point of view and remote sensing methods. Moreover, the recent research on UAV photogrammetry platform equipment and flight planning actively contribute in this sense for a scaling improvement and cost-benefits balance. Frequently, the experiences on articulated topographic profiles in archaeological excavations require not only a multi-sensor approach but also and above all a multiscale one. According to this line, in a general time-cost ration framework, the geometric content of the generated DSMs should be complete of nadir and oblique point of view for the accurate 3D reconstruction of both upstanding buildings and excavations. In the same way, also the radiometric content closely depends on sensor payload quality and is strictly affected by excavation site condition, related to the site material and light. In this research, carried out in the impressive archaeological site of the ancient city of Hierapolis in Phrygia (Turkey) in the autumn 2019 campaign, the main goal was to evaluate and validate the overall performance of a novel UAV fix-wing ultralight platform with onboard GNSS receiver for RTK/PPK processing of cameras positioning and with the possibility of oblique images capturing. The expected contribute in terms of the acquisition, processing time, radiometric enhancement and geometry 3D reconstruction will be explored with preliminary test and outcomes, and with the results of the high-scale DSM and orthoimage generation of the complete Hierapolis site.

The cultural heritage and the ways in which it is today studied and analysed as well as disseminated and enhanced for the purposes of conservation, requires high attention in the choice of 3D survey and modelling methods. This manuscript investigates the possible integrations and fusion of methods and data, among the vast availability of image and range based systems, especially in the sphere of low cost techniques, which in the context of heritage documentation makes the whole and complex process of conservation more sustainable. The investigation is carried out on a historical fountain that includes a quantity of cultural values and the need to document its context: its location in the historical Valentino of Turin park, its architectural values and the geometry of the complex typically related to the tastes of the late XIX century that consist in the extreme refinement of the statuary complexes and the underground portion with the technological equipment for the activation of the water games. Basically, it will be possible to appreciate solved issues and permanent criticalities derived from the integration of close range and UAV photogrammetry techniques in addition to the LiDAR survey, both classic from a fixed position, and in the portable scanner mode, based on SLAM technology.

The paper provides some operative replies to evaluate the effectiveness and the critical issues of the simultaneous localisation and mapping (SLAM)-based mobile mapping system (MMS) called ZEB by GeoSLAM™ https://geoslam.com/technology/ . In these last years, this type of handheld 3D mapping technology has increasingly developed the framework of portable solutions for close-range mapping systems that have mainly been devoted to mapping the indoor building spaces of enclosed or underground environments, such as forestry applications and tunnels or mines. The research introduces a set of test datasets related to the documentation of landscape contexts or the 3D modelling of architectural complexes. These datasets are used to validate the accuracy and informative content richness about ZEB point clouds in stand-alone solutions and in cases of combined applications of this technology with multisensor survey approaches. In detail, the proposed validation method follows the fulfilment of the endorsed approach by use of root mean square error (RMSE) evaluation and deviation analysis assessment of point clouds between SLAM-based data and 3D point cloud surfaces computed by more precise measurement methods to evaluate the accuracy of the proposed approach. Furthermore, this study specifies the suitable scale for possible handlings about these peculiar point clouds and uses the profile extraction method in addition to feature analyses such as corner and plane deviation analysis of architectural elements. Finally, because of the experiences reported in the literature and performed in this work, a possible reversal is suggested. If in the 2000s, most studies focused on intelligently reducing the light detection and ranging (LiDAR) point clouds where they presented redundant and not useful information, contrariwise, in this sense, the use of MMS methods is proposed to be firstly considered and then to increase the information only wherever needed with more accurate high-scale methods.

In the framework of the digital documentation of complex environments the advanced Geomatics researches offers integrated solution and multi-sensor strategies for the 3D accurate reconstruction of stratified structures and articulated volumes in the heritage domain. The use of handheld devices for rapid mapping, both image- and range-based, can help the production of suitable easy-to use and easy-navigable 3D model for documentation projects. These types of reality-based modelling could support, with their tailored integrated geometric and radiometric aspects, valorisation and communication projects including virtual reconstructions, interactive navigation settings, immersive reality for dissemination purposes and evoking past places and atmospheres. The aim of this research is localized within the “Torino 1911” project, led by the University of San Diego (California) in cooperation with the PoliTo. The entire project is conceived for multi-scale reconstruction of the real and no longer existing structures in the whole park space of more than 400,000 m2, for a virtual and immersive visualization of the Turin 1911 International “Fabulous Exposition” event, settled in the Valentino Park. Particularly, in the presented research, a 3D metric documentation workflow is proposed and validated in order to integrate the potentialities of LiDAR mapping by handheld SLAM-based device, the ZEB REVO Real Time instrument by GeoSLAM (2017 release), instead of TLS consolidated systems. Starting from these kind of models, the crucial aspects of the trajectories performances in the 3D reconstruction and the radiometric content from imaging approaches are considered, specifically by means of compared use of common DSLR cameras and portable sensors.

The analysis of terraced heritage has implications in many different fields of study, as it is shaped itself by natural, socioeconomic, and cultural dynamics. Given that their abandonment impoverishes territories and communities and raises natural, especially hydrogeological hazards, and that their deactivation leads to a loss of cultural identity, this paper aims to study rapid mapping systems for their detection. Since a deep relation between high land division and the use of terraces for the exploitation of territories has been recognized, a first detection method is based on cadastral maps. The joint use of regional-scale digital elevation models (DEMs) and cadastral dataset polygons, based on a model that typically uses GIS analyses, identifies areas with a high probability of terracing. A second method is based on the use of new technologies for very high-scale data collection. The DEM models derived from UAV (unmanned aerial vehicle) photogrammetry, given their ability to determine the micro-topographical characterization of the terrain as well as the most expensive on-site techniques, can be considered an excellent low-cost means by which to locate terraced heritage. The proposed work includes comparative testing between methods implying GIS-based analysis of slope models. It aims to highlight the effectiveness of using both methods: regional-scale DEMs and cadastral maps to detect a high probability of terrace localization, and DEMs derived from the use of low-altitude aerial data and structure from motion (SfM) algorithms, which have greatly and effectively increased the use of aerial drone photogrammetry.

The project is part of the wider application and subsequent spread of innovative digital technologies involving robotic systems. Modern society needs knowledge and investigation of the environment and of the related built landscape; therefore it increasingly requires new types of information. The goal can be achieved through the innovative integration of methods to set new analysis strategies for the knowledge of the built heritage and cultural landscape. The experimental cooperation between different disciplines and the related tools and techniques, which this work suggests for the analysis of the architectural heritage and the historical territory, are the following: – 3D metric survey techniques with active and passive sensors – the latter operating in both terrestrial mode and by aerial pointof view. In some circumstances, beyond the use of terrestrial LiDAR, even the newest mobile mapping system using SLAMtechnology (simultaneous localization and mapping) has been tested. – Techniques of non-destructive investigation, such as geophysical analysis of the subsoil and built structures, in particularGPR (Ground Penetrating Radar) techniques. – Historic and stratigraphic surveys carried out primarily through the study and interpretation of documentary sources,cartography and historical iconography, closely related to the existing data or latent material. The experience through the application of these techniques of investigation connected to the built spaces and to the manmade environments has been achieved with the aim of improving the ability to analyse the occurred transformations/layers over time and no longer directly readable or interpretable on manufactured evidence.

It is important nowadays to underline some relevant topics concerning the effective contribution of 3D high detailed products derived from innovation and integration of Geomatics technologies, allowing a remarkable development in descriptive metric capabilities, supporting and improving the material recording, representation, analysis and characterization about alteration of the constructive systems. Considering the relevance of the complex interdisciplinary research of these issues that move around the Cultural Heritage safeguard and due to its extreme vulnerability, these models must give a response to different problems. Primarily they has to provide complete models on which to pursue accurate morpho-dimensional documentation, and to base structural assessment, decay investigations, and consequently to underpin restoration practices and support operational workflow in CH assets monitoring. Some peculiarities of new methods for semi-automatic processing algorithms are thus evidenced, advantaging their proficiency to behave as tools for a more sustainable approach in the general process of preservation and protection. Specifically about the ancient masonries documentation, the chance of using digital products derived from very high scale models, as the detailed orthoimages projection and surfaces development offers many opportunities. Here, a late-medieval stratified dovecote tower in Verolengo (TO) with a particular trunk-conical shape had been analysed in order to reconstruct an identity and a historical and architectural framework, de facto not recognized yet. A 3D reconstruction by dense matching techniques will be presented, in the complex context that are the vertical high buildings, presenting one of the highest level of vulnerability. The importance of the 3D model availability, closely connected to dense radiometric information, has been particularly expressed in two main direction for the diagnosis both of volumetric structure assessment and the material characterization of the mixed masonries walls.

One of the challenging purposes that must be undertaken by applied geomatics, is the need of monitoring by documenting continuously over time the evolution of urban spaces. Nowadays, this is a subject of great interest and study, mainly in case of sudden emergency events that implicate urban areas and specific historical buildings of our heritage. The newest Geomatics technique solutions must enable the demands of damage documentation, risk assessment, management and data sharing as efficiently as possible, in relation to the danger condition, to the accessibility constraints of areas and to the tight deadlines needs. In August 24th 2016, the first earthquake hit the area of central Italy with a magnitude of 6.0; since then, the earth never stop shaking in a wide area in the middle of Italy. On 26th and 30th of October, two other big seismic events were recorded (magnitude 5.9 and 6.5) and the already damaged built heritage were struck again. Since the beginning of the emergency all the available resources (human and material) were deployed and the world of researchers is trying to furnish an effective contribute as well. Politecnico di Torino, in coordination with the national institutions, is deploying people, expertise and resources. The geomatics research group and the connected Disaster Recovery team (DIRECT - http://areeweb.polito.it/direct/) is part of this process and is working in deep contact and collaboration with the Remotely Piloted Aircraft Systems (RPAS) group of the Italian Firefighter. Starting from the first earthquake the late medieval religious complex of S. Agostino has been carefully monitored and detected, using a multi-perspective oblique imagery strategy with the aim to achieve 3D aerial and terrestrial models, in a multi-temporal perspective concerning three different time situation.

In sudden emergency contexts that affect urban centres and built heritage, the latest Geomatics technique solutions must enable the demands of damage documentation, risk assessment, management and data sharing as efficiently as possible, in relation to the danger condition, to the accessibility constraints of areas and to the tight deadlines needs. In recent times, Unmanned Vehicle System (UAV) equipped with cameras are more and more involved in aerial survey and reconnaissance missions, and they are behaving in a very cost-effective way in the direction of 3D documentation and preliminary damage assessment. More and more UAV equipment with low-cost sensors must become, in the future, suitable in every situation of documentation, but above all in damages and uncertainty frameworks. Rapidity in acquisition times and low-cost sensors are challenging marks, and they could be taken into consideration maybe with time spending processing. The paper will analyze and try to classify the information content in 3D aerial and terrestrial models and the importance of metric and non-metric withdrawable information that should be suitable for further uses, as the structural analysis one. The test area is an experience of Team Direct from Politecnico di Torino in centre Italy, where a strong earthquake occurred in August 2016. This study is carried out on a stand-alone damaged building in Pescara del Tronto (AP), with a multi-sensor 3D survey. The aim is to evaluate the contribution of terrestrial and aerial quick documentation by a SLAM based LiDAR and a camera equipped multirotor UAV, for a first reconnaissance inspection and modelling in terms of level of details, metric and non-metric information.

Mobile mapping systems are increasingly developing ad hoc solution and integrated approaches for rapid and accurate 3D digitization in different operating environments belonging to built heritage assets. The use of emerging compact, portable and low-cost solution for imaging and ranging well fits in the purposes of mapping complex indoor spaces especially for narrow and underground ones (tunnels, mines, caves and ancient spaces), that are very challenging contexts in which to experiment integrated technological solutions and tailored workflows. In these cases, the main key issues are generally the difficulty in the seamless positioning and the complete and successful metric-radiometric content association in metric surface, due to the reduced manoeuvring space and complex lighting conditions. The prevalent goals for which the 3D digitization could be conceived are, beyond the accurate metric documentation, the analysis of mutual relations of volumes in complex structures, the virtual reconstruction and navigation of spaces with reduced accessibility for dissemination aims. The new SLAM-based positioning solutions implemented in some recent portable systems for indoor/outdoor mapping are increasingly developing and favoured by geometric features extraction algorithms even in traveling through complex and irregular environments. In parallel, the possibility to exploit the advances in digital photogrammetry algorithms for image matching and dense reconstruction using action-cam, compact and fisheye cameras allows to deploy investigation solutions even in complex environments at first sight impossible to map by photogrammetric approach. Here within the F.I.N.E. benchmark in the site of the San Vigilio Castle (Bergamo) and the “nottole” tunnels, a fusion-based workflow is proposed. It is focused on the purposes of providing radiometrically enriched 3D data from the possibility to colourized ZEB point cloud and a textured mesh surfaces with an oriented image block, taking care of the time processing steps optimization.

The LiDAR technology has aroused considerable interest in the field of structural study of historical buildings, aimed at the structural assessment in the presence of different states of stresses and at the evaluation of the health status.The interest is due mostly by the ability of generating models of the built structures being able to predetermine different levels of schematization, two-dimensional and three-dimensional, in order to be able to perform evaluation processes assigning simplified geometric contents that correspond to the physical reality of the artefacts.This paper intends to report some results of these experiences applied in archaeological domain, to the so-called Baths-Church at Hierapolis in Phrygia (Pamukkale, TR). In particular, the generation of accurate models from dense clouds and their reduction to models with simplified geometries too, is explored, with the further aim of testing automated strategies for features detection and editing process that leads to appropriate models for visual and analytical structural assessment. The accuracy and density parameters of the LiDAR clouds will be analysed to derive orthophotos and continuous mesh models, both to obtain the best results from the application of research algorithms such as region growing to detect blocks, and to allow visual analysis on digital models and not on site.The ability to determine with high accuracy both the size and the anomalies of the wall systems (out of plumb and other rotation or local mechanisms of collapse), together with the possibility of identifying the lay of the individual drywall blocks and also the signs of cracks and collapses, allow deriving suitable models both for FE (Finite Elements) analysis and DE (Discrete Elements) analysis, as well as analytical ones.

This paper proposes an emblematic project where several multi-sensor strategies for spatial data acquisition and management, range based and image based, were combined to create a series of integrated territorial and architectural scale products characterized by a rich multi-content nature. The work presented here was finalized in a test site that is composed by an ensemble of diversified cultural deposits; the objects that were surveyed and modelled range from the landscape with its widespread mining sites, the main tower with its defensive role, the urban configuration of the settlement, the building systems and techniques, a medieval mine. For this reason, the Rocca of San Silvestro represented a perfect test case, due to its complex and multi-stratified character. This archaeological site is a medieval fortified village near the municipality of Campiglia Marittima (LI), Italy. The Rocca is part of an Archaeological Mines Park and is included in the Parchi della Val di Cornia (a system of archaeological parks, natural parks and museums in the south-west of Tuscany). The fundamental role of a deep knowledge about a cultural artefact before the planning of a restoration and valorisation project is globally recognized; the qualitative and quantitative knowledge provided by geomatics techniques is part of this process. The paper will present the different techniques that were used, the products that were obtained and will focus on some mapping and WEB GIS applications and analyses that were performed and considerations that were made.

The recent seismic swarms, occurred in Italy since August 2016, outlined the importance of deepen Geomatics researches for the validation of new strategies aimed at rapid-mapping and documenting differently accessible and complex environments, as in urban contexts and damaged built heritage. In the emergency response, the crucial exploitation of technological advances should obtain and efficiently organize high-scale reliable geospatial data for the early warning, impact, and recovery phases. Fulfilling these issues, among others, the Copernicus EMS, has played by now an important role in immediate and extensive damage reconnaissance, as in the case of Centre Italy. Nevertheless, the use of remote sensing data is still affected by a problem of point-of-view, scale and detectable detail. Nadir images, airborne or satellite, in fact, strongly limited the confidence level of these products. The subjectivity of the operator involvement is still an open issue, both in the first fieldwork assessment, and in the following operational approach of interpretative damage detection and rapid mapping production. To overcome these limits, the introduction of UAV platforms for photogrammetric purposes, has proven to be a sustainable approach in terms of time savings, operators’ safety, reliability and accuracy of results: the nadir and oblique integration can provide large multiscale models, with the fundamental information related to the façades conditions. The presented research, conducted within the Central Italy earthquakes events, will focus on potentialities and limits of UAV photogrammetry in the two documented sites: Pescara del Tronto and Accumoli. Here, the aim is not limited to describe a series of strategies for georeferencing, blocks orientation and multitemporal co-registration solutions, but also to validate the implemented pipelines as a workflow that could be integrated in the operative intervention for emergency response in early impact activities. Thus, it would be possible to use this 3D metric products as a reference-data for significative improvements of reliability in typical visual inspection and mapping, flanking the traditional nadir airborne- or satellite-based products. The UAV acquisitions performed in two damaged villages are displayed, in order to underline the implication of the spatial information embedded in DSM reconstruction and 3D models, supporting more reliable damage assessments.

One of the last and more pressing requests to the researchers working in the field of Geomatics is to research, validate, and propose new strategies for the rapid mapping of different contexts, with low-cost solutions. The continuous implementation of image-matching algorithms and their use in structure from motion (SfM) software allow using new sensors and implementing new strategies for the production of 3D models starting from an image-based approach. In the last years, another central issue for the researchers has been related with the documentation of cultural heritage (CH) artifacts using different sensors and techniques. In the experience presented in this paper, the attention was focused on these two central aspects: a test of a commercial off-the-shelf (COTS) steadicamera for the rapid 3D documentation of two cultural heritage artifacts was proposed. The two sites chosen to evaluate this mass market sensor were as follows: the Basilica of San Nicola (Tolentino, MC, Marche Region, Central Italy) and the Castello del Valentino (Torino, TO, Piedmont Region, North Italy). The metric products obtained with the Steadicam were compared with more consolidated techniques such as close-range photogrammetry (CRP) and terrestrial laser scanner (TLS). The products derived from the different techniques were then evaluated and compared, and an overall assess of the use of this new solution was made.

The paper focuses on the exploration of the suitability and the discretization of applicability issues about advanced surveying integrated techniques, mainly based on image-based approaches compared and integrated to range-based ones that have been developed with the use of the cutting-edge solutions tested on field. The investigated techniques integrate both technological devices for 3D data acquisition and thus editing and management systems to handle metric models and multi-dimensional data in a geospatial perspective, in order to innovate and speed up the extraction of information during the archaeological excavation activities. These factors, have been experienced in the outstanding site of the Hierapolis of Phrygia ancient city (Turkey), downstream the 2017 surveying missions, in order to produce high-scale metric deliverables in terms of high-detailed Digital Surface Models (DSM), 3D continuous surface models and high-resolution orthoimages products. In particular, the potentialities in the use of UAV platforms for low altitude acquisitions in aerial photogrammetric approach, together with terrestrial panoramic acquisitions (Trimble V10 imaging rover), have been investigated with a comparison toward consolidated Terrestrial Laser Scanning (TLS) measurements. One of the main purposes of the paper is to evaluate the results offered by the technologies used independently and using integrated approaches. A section of the study in fact, is specifically dedicated to experimenting the union of different sensor dense clouds: both dense clouds derived from UAV have been integrated with terrestrial Lidar clouds, to evaluate their fusion. Different test cases have been considered, representing typical situations that can be encountered in archaeological sites.

[EN] Unmanned aerial vehicle (UAV) photogrammetry has shown a very rapid development in many fields, especially in archaeological excavation areas and architectural complexes, where it offers a detailed generation of three-dimensional (3D) data including the possibility of updating over time. It also proves to be a very flexible tool applicable to many types of complex areas with a variety of different features. The use of aerial acquisition provides highly effective results, adding to both rapid capture and lower costs. In fact, today in the field of archaeological research, great efforts are invested in the generation of very large-scale models and orthophotos, and the technology seems to promise further future developments, not only from the terrestrial (orthogonal) point of view, but also from the nadiral direction from a low altitude, as a preferential and often optimal point of view. Here an effective workflow for photogrammetric product generation is presented for selected case studies in some monumental areas of ancient Hierapolis in Phrygia (Turkey), in which the Italian Archaeological Mission of Hierapolis (MAIER) has been working since the 1960s. The recent experiences achieved by UAV photogrammetry are quite innovative. The variety and complexity of the buildings, as well as the height of their ruins, offer numerous challenges, which are interesting to deal with. The 3D aerial survey was performed for multiple purposes with the eBee system by Sensefly. Specific attention was paid to the digital surface model (DSM) and aerial orthoimages of three test areas: the Plutonium area; the Thermal Bath-Church; and the Necropolis. Starting from the same technical approach, a comparative assesment among the three sites was carried out, taking into account the specific goals, the type of the structure and the terrain conformation., [ES] La fotogrametría con vehículos aéresos no tripulados (Unmanned Aerial vehicle, UAV) ha mostrado un desarrollo muy rápido en muchos campos, especialmente en áreas de excavación arqueológica y complejos arquitectónicos, donde ofrece una detallada generación de datos tridimensionales (3D), junto con su actualización en el tiempo. También demuestra ser una herramienta muy flexible aplicable en muchos tipos de áreas complejas, con diferentes características formales. El uso de la toma aérea proporciona hoy resultados altamente efectivos, lo que aumenta la rapidez de adquisición y menores costes. De hecho, hoy en día en el campo de la investigación arqueológica, se invierten grandes esfuerzos a la hora de generar modelos y ortoimágenes a grandes escalas, y parece prometer más desarrollos futuros, no sólo desde el punto de vista terrestre (ortogonal), sino también con dirección nadiral, desde baja altitud, como punto de vista preferencial y óptimo. Aquí se presenta un flujo de trabajo eficaz que permite generar productos fotogramétricos en varios casos de estudio en áreas monumentales de la antigua Hierápolis de Frigia (Turquía), donde la Misión Arqueológica Italiana de Hierápolis (MAIER) ha estado funcionando desde los años 1960. Estas experiencias logradas con la fotogrametría UAV son bastante innovadoras. La variedad y la complejidad de los edificios, así como la altura de sus ruinas ofrecen numerosos puntos problemáticos que son interesantes de tratar. El levantamiento aéreo 3D se realizó con múltiples propósitos por medio del sistema eBee de Sensefly. Se prestó especial atención al Modelo Digital de Superficie (MDS) y a las ortoimágenes aéreas en tres áreas de prueba: el área de Plutonio; la Iglesia-Baño Termal; y la Necrópolis. Partiendo del mismo enfoque técnico, se ofreció una evaluación comparativa de los tres sitios, teniendo en cuenta los objetivos específicos, el tipo de estructura y la configuración del terreno.

(TLS, Terrestrial Laser Scanning), and large scale mapping derived by UAV (Unmanned Aerial Vehicle) survey. This paper refers an example of 3D survey and reality based modelling applied on landscape and architectural assets. The choice of methods for documentation, in terms of survey techniques, depends primarily on issues and features of the area. The achieved experience, allow to consider that the easy handling of TLS has enabled the use in limited spaces among buildings and collapsed roofs, but the topographic measure of GCPs (Ground Control Points), neither by total station nor by GPS/RTK technique, was easily feasible. Even more than proving the ability of the integration of TLS and UAV photogrammetry to achieve a multi-source and multi-scale whole model of a village, the experience has been a test to experiment the registration of terrestrial clouds with the support of control points derived by UAV survey and finally, a comparison among different strategies of clouds registration is reported. Analysing for each approach a number of parameters (number of clouds registration, number of needed points, processing time, overall accuracy) the further comparisons have been achieved. The test revealed that it is possible to decrease the large number of terrestrial control points when their determination by topographical measures is difficult, and it is possible to combine the techniques not only for the integration of the final 3Dmodel, but also to solve and make the initial stage of the drafting process more effective.

The paper describes an activity conducted by a multi-disciplinary research group (architecture, civil engineering, technology, geomatics) for the mechanical evaluation of a timber floor belonging to a historic residential building located in the city center of Torino. The floor was made of beams of solid wood and wooden boards and presented a mid-span deflection. Since the floor structure was hidden by a suspended ceiling, the difficulty was to determine with precision all the geometrical characteristics of the main beam and its creep with the aim of verifying its mechanical resistance and stiffness. Through an accurate application of laser-scanner technique, it was possible to carry out the precise assessment of the structure.

This paper retraces some research activities and application of 3D survey techniques and Building Information Modelling (BIM) in the environment of Cultural Heritage. It describes the diffusion of as-built BIM approach in the last years in Heritage Assets management, the so-called Built Heritage Information Modelling/Management (BHIMM or HBIM), that is nowadays an important and sustainable perspective in documentation and administration of historic buildings and structures. The work focuses the documentation derived from 3D survey techniques that can be understood like a significant and unavoidable knowledge base for the BIM conception and modelling, in the perspective of a coherent and complete management and valorisation of CH. It deepens potentialities, offered by 3D integrated survey techniques, to acquire productively and quite easilymany 3D information, not only geometrical but also radiometric attributes, helping the recognition, interpretation and characterization of state of conservation and degradation of architectural elements. From these data, they provide more and more high descriptive models corresponding to the geometrical complexity of buildings or aggregates in the well-known 5D (3D + time and cost dimensions). Points clouds derived from 3D survey acquisition (aerial and terrestrial photogrammetry, LiDAR and their integration) are reality-based models that can be use in a semi-automatic way to manage, interpret, and moderately simplify geometrical shapes of historical buildings that are examples, as is well known, of non-regular and complex geometry, instead of modern constructions with simple and regular ones. In the paper, some of these issues are addressed and analyzed through some experiences regarding the creation and the managing of HBIMprojects on historical heritage at different scales, using different platforms and various workflow. The paper focuses on LiDAR data handling with the aim to manage and extract geometrical information; on development and optimization of semi-automatic process of segmentation, recognition and modelling of historical shapes of complex structures; on communication of historical heritage by virtual and augmented reality (VR/AR) in a 3D reconstruction of buildings aggregates from a LiDAR and UAV survey. The HBIM model have been implemented and optimized to be managed and browse by mobile devices for not only touristic or informative scopes, but also to ensure that HBIM platforms will become more easy and valuable tools helping all professionals of AEC involved in the documentation and valorisation process, that nowadays more and more distinguish CH policies.

The archaeological researches and more generally the Cultural Heritage (CH) documentation and conservation activities have been favourably disposed to the use of new technologies, with renewed and increasing interest in the use of integrated techniques. In the field of Geomatics the advent of advanced technologies has allowed and facilitated multidisciplinary studies as well as combined approaches to the documentation in various contexts. The production of spatially located data (e.g. from active or passive sensors placed in different system segments, from terrestrial to aerial to satellite position) and their interoperability from different source, with the help of Geographic Information Systems (GIS), were then made easier. The work has the aim of investigating the integration of multiple data derived from aerial photogrammetry products through Unmanned Aerial Vehicles (UAV) survey, from geophysical Ground Penetrating Radar (GPR) prospection technique and analysis of historical ma ps. An archaeological area in the south of Piedmont (Italy), next to the ancient Roman settlement of Pollentia, has been the test case. The present fulfilled test was objected to exclude ancient presences, although this type of workflow is generally aimed to analyse and compare results in order to formulate some hypothesis about the potential presence of submerged elements or built substructures in the investigated area

[EN] In areas of archaeological excavation with architectural complexes, the generation of 3D data and their spatial information updating can now benefit from UAV photogrammetry. This technique shows a very rapid development in many fields, as it provides effective results for high-resolution and detailed surfaces, adding to both quickness and suistainable costs, quite irrespective of the form and extension. That is very important in Documentation phases of Cultural Heritage. In the field of archaeological researches, the nadir view from low altitude has always been a preferential point of view, then the generation of very large-scale models and orthophotos is of great interest today, and it seems to promise high future developments. So the paper focuses on a workflow to obtain photogrammetrical products generation using eBee system, by Sensefly, of growing popularity in the scenario of survey techniques. The potential of outcomes is also given by the selected monumental case studies in the city of Hierapolis in Phrygian, on which the MAIER (Italian archaeological Mission of Hierapolis) operates from the 60s of the twentieth century. The variety and complexity of the buildings, as well as the height of their ruins offers numerous trouble spots that is interesting to deal. A particular attention on the accuracy of DSM (Digital Surface Model) will be evaluated and reported thanks to the GCPs (ground control points) that have been easily measured since these aerial photogrammetry experiences by UAV are the last of extensive previous metric surveys conducted in the recent past.

In recent years, laser scanning technique has aroused huge interest in the field of structural analysis of historical built heritage aimed at the evaluation of different static stress states and the assessment of health conditions. Nowadays it is possible to generate and manage multi-scale and simplified 3D and 2D structural models featured by different levels of detail, on which static assessment can be applied. The Geomatics group of the Politecnico di Torino, in cooperation with the Structural Engineering group, has started a series of experiences and studies oriented to outline “good practices” for the models generation of different historical structures, from ancient stone-walls, up to wooden beams, thin vaults and reinforced concrete structures. This paper shows some results, issues and considerations of such experiences: an in-depth analysis about the generation of adequate 3D models from point clouds and their geometrical generalization is carried out, which comes with the selection of the best strategies and algorithms for the automation of editing. The selected case studies are quite different regarding the period in which they were built and, therefore, regarding their building systems. The aim is to highlight tools already available for the automatic and semiautomatic geometrical entities recognition and features extraction which are necessary to develop geometrical models useful for Finite Element Method (FEM). The case studies consist in: the large masonry blocks laid almost dry of the ancient suburban bath of Hierapolis (TK); the thin wooden vault and wooden timbers roof of the large sloping Baroque roofs, both belonging to the seventeenth century Castle of Valentino in Turin; the latest is the reinforced concrete vault of the Paraboloid of Casale Monferrato (AL).

[EN] This paper discusses some enhancements concerning 3D modelling and integration of 3D data from aerial and terrestrial sensors, developed by geomatics in the field of Cultural Heritage metric documentation. For archaeological purposes, it is interesting to deal with the considerable advantages in term of sustainability (automated acquisition, quickness, precision, time and cost cutting) of new multi-sensors approaches for the data acquisition and the management phases. In particular, the UAV (Unmanned Aerial Vehicles) Photogrammetry with the joint use of nadiral and oblique cameras, can be valuably combined with the large-scale details reach by terrestrial LiDAR in vast areas or complex objects, especially in mostly vertical sized objects. Here it will be reported an experience of integrated 3D survey in an archaeological context in Piedmont region (Italy), the Hercules Fountain in the gardens of the Venaria Reale. It has witnessed several historical phases during centuries, from its construction in 16th to the disuse and dismantling in 17th, up to the 21th century in which it was lastly brought back to light. The goal of the test is the generation of a 3D continuous model of the site for documentation purposes, future consolidation and enhancement projects finalized to a public promotion. To meet these aims a terrestrial laser scanning (TLS) survey has been designed combining terrestrial and UAV photogrammetric data acquisition, to produce a high detailed 3D textured model from which infer standard 2D drawings, digital orthoimages and further 3D releases. The entire workflow and outputs were compared together to evaluate the effectiveness of each elaboration according to the survey goals

In this paper, a series of topics, concerning acquisition, communication, and the analysis of buildings will be discussed. In particular, a strategy aimed at exploiting the visual potentials of reality-based models, will be described inside render engines, real-time applications, as well as their role for the production of conventional drawing for documenting and studying built heritage. This methodology is inspired by pipelines coming from computer-generated imagery (CGI) and the video game industry: areas of research that are progressively showing an increasing interest towards the world of photogrammetry remote sensing, in particular for the new possibilities offered by Structure from Motion (SfM)/Multi View Stereo (MVS) in terms of automatic texturing of complex shapes. Quad-dominant remeshing, displaced subdivision surfaces, and accurate interactive/ automatic parametrization are the main points of this workflow, whose final goal is the achievement of multipurpose models, which are capable to comply with graphic codes of traditional survey, as well as semantic enrichment, and, last but not least, data compression/portability and texture reliability under different lighting conditions.