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Cultural heritage information systems, such as H-BIM, are becoming more and more widespread today, thanks to their potential to bring together, around a 3D representation, the wealth of knowledge related to a given object of study. However, the reconstruction of such tools starting from 3D architectural surveying is still largely deemed as a lengthy and time-consuming process, with inherent complexities related to managing and interpreting unstructured and unorganized data derived, e.g., from laser scanning or photogrammetry. Tackling this issue and starting from reality-based surveying, the purpose of this paper is to semi-automatically reconstruct parametric representations for H-BIM-related uses, by means of the most recent 3D data classification techniques that exploit Artificial Intelligence (AI). The presented methodology consists of a first semantic segmentation phase, aiming at the automatic recognition through AI of architectural elements of historic buildings within points clouds; a Random Forest classifier is used for the classification task, evaluating each time the performance of the predictive model. At a second stage, visual programming techniques are applied to the reconstruction of a conceptual mock-up of each detected element and to the subsequent propagation of the 3D information to other objects with similar characteristics. The resulting parametric model can be used for heritage preservation and dissemination purposes, as common practices implemented in modern H-BIM documentation systems. The methodology is tailored to representative case studies related to the typology of the medieval cloister and scattered over the Tuscan territory.

International audience; Artificial Intelligence (AI) applications to architectural heritage usher promising evolutions in the Graphic arts and design field, as increasingly automated segmentation techniques can be applied to digital and numeric models for the semantic interpretation of survey data and subsequent recon-struction of conceptual and parametric 3D representations. Increasingly automated systems for the semantic description and classification of 3D data are indeed in ever-growing demand, also in view of optimizing Scan-to-BIM processes. In this context, the present contribution describes a semi-au-tomated methodological approach aimed at building semantically rich and intelligible representations starting from survey data. This approach features two core foundations: firstly, the classification and subsequent propagation of architectural types, by means of Artificial Intelligence (AI) algorithms applied to the point clouds; secondly, the reconstruction, in Building Information Modelling (BIM) environment, of the detected element classes, via information transmission procedures and visual programming languages. The analysis of the proposed methodology applies to representative case studies referring to selected settings of the Pisa Charterhouse.

This paper identifies the application domain, context of use, processes and goals of low-cost street-level photogrammetry after urban disasters. The proposal seeks a synergy between top-down and bottom-up initiatives carried out by different actors during the humanitarian response phase in data scarce contexts. By focusing on the self-organisation capacities of local people, this paper suggests using collaborative photogrammetry to empower communities hit by disasters and foster their active participation in recovery and reconstruction planning. It shows that this task may prove technically challenging depending on the specifics of the collected imagery and develops a grounded framework to produce user-centred image acquisition guidelines and fit-for-purpose photogrammetric reconstruction workflows, useful in future post-disaster scenarios. To this end, it presents an in-depth analysis of a collaborative photographic mapping initiative undergone by a group of citizen-scientists after the 2016 Central Italy earthquake, followed by the explorative processing of some sample datasets. Specifically, the paper firstly presents a visual ethnographic study of the photographic material uploaded by participants from September 2016 to November 2018 in the two Italian municipalities of Arquata del Tronto and Norcia. Secondly, it illustrates from a technical point of view issues concerning the processing of crowdsourced data (e.g. image filtering, selection, quality, semantic content and 3D model scaling) and discusses the viability of using it to enrich the pool of geo-information available to stakeholders and decision-makers. Final considerations are discussed as part of a grounded framework for future guidelines tailored to multiple goals and data processing scenarios.

Purpose of this paper is to compare different methods for the assessment of earthquake-induced damage on buildings based on survey data, referring to the case study of Castelluccio di Norcia. The seismic events that occurred in Central Italy in 2016 threatened the future of many villages located along the Apennine ridge straddling the Regions of Umbria, Marche, Abruzzo and Lazio: in Castelluccio di Norcia, a minor historical center in the Municipality of Norcia (Umbria), the earthquake occurred on August the 24th caused some damage on localized buildings, but the strongest seismic event – the one occurred on October the 30th and with magnitude Mw 6.5, provoked numerous collapses and widespread failure on several buildings of the village, razing to the ground almost the 60 % of the built heritage. After the two earthquakes respectively, the Fire Brigade organized a reconnaissance campaign and flew over the village via UAVs (Unmanned Aerial Vehicles). By acquiring the videos recorded in this framework, that are currently available on the net and originally not recorded for specific survey purposes, the authors produced 3D models of the village allowing to compare the configuration of Castelluccio in the phases pre- and post- the destructive event of 30th October: in fact, since the level of damage after the earthquake of August the 24th was very low, the model resulting from the video recorded after this earthquake could be used as a model showing the layout of the village before the main struck of October. The result of this study is the Damage Degree Evaluation (DDE) and the following definition of a map showing for each building its class of damage, according to the distinction provided by European Macro-seismic Scale EMS98. On the other hand, another damage level map was studied: the Civil Protection requested, immediately after the earthquake and for the management of disaster response activities, the activation of the COPERNICUS project, providing for the detection of most damaged buildings of the village for an early census of the non-safe areas. The map of the damage level produced within this project is of course more accurate and precise, since it was collected through different acquisition systems: UAV, close-range photogrammetry, LiDAR (Light Detection And Ranging) and SLAM (Simultaneous Location and Mapping)-based mapping. This paper proposes a comparison between the two different DDEs, in order to define whether the first method, even if based on data downloaded via the web and therefore at lower resolution, and even if acquired with a more rapid evaluation procedure not providing for ground-based surveys, can lead to the construction of damage level maps that are plausible and realistic. The question is if the first method of DDE, even if less accurate, can allow to obtain results that are satisfactory and useful in the process of management and monitoring of natural hazards, providing support for the several implied institutions, in terms of information on catastrophes and first disaster rescue management.

In the last decade, in the field of conservation of historic buildings, several research projects have shown the potential of applying BIM technology to architectural heritage. However, the use of BIM for historic buildings (HBIM) is still evolving. This paper presents an application of Building Information Modelling targeted to the development of a restauration proposal for the ex-church of San Quirico all’Olivo in Lucca, Tuscany. Following a brief review of the state-of-the-art of BIM applied to architectural heritage, the paper shows the results of a study that included 3D architectural survey with Structure-from-Motion methodology, critical analysis of historical archival and bibliographic sources, analysis of the conservation status of the building, proposal for its conservation and enhancement.HBIM methodology has been critically applied to all the phases of the project. This study also explores the possibility of organizing the BIM model into temporal phases, integrating documentation in a structured and easily accessible way. In our study, we also chose to link the 3D point cloud to the model, in order to increase the level of information; the 3D survey, therefore, is both the starting point for modelling, and represents a source of information within the model, to be recalled when required.

Cultural heritage includes several cases of missing architectural element or entire buildings, due to destruction, replacement or radical changes caused over time by other structures. The investigation of these lost elements aimed at their virtual reconstruction, for both scientific and cultural-leisure applications, is therefore a topic of great interest. To this purpose, methodologies for surveying and photogrammetric processing provide a very powerful tool, extracting descriptive and geometric information, both 2-and 3-D, using diverse archive images. This paper presents the issues related to the use of archive images in photogrammetry, pointing out the need for an integrated approach to operations of virtual reconstruction of lost volumes. This approach provides a multidisciplinary effort, in order to evaluate all iconographic sources, of which images processed by geomatics techniques are a component. The paper also presents the early results of a reconstruction project of the Palazzo di Cosimo de’ Medici, in the Fortezza Vecchia site (Livorno, Italy), heavily damaged by World War II bombings and subsequently razed.

International audience; This work presents a semi-automatic approach to the 3D reconstruction of Heritage-Building Information Models from point clouds based on machine learning techniques. The use of digital information systems leveraging on three-dimensional (3D) representations in architectural heritage documentation and analysis is ever increasing. For the creation of such repositories, reality-based surveying techniques, such as photogrammetry and laser scanning, allow the fast collection of reliable digital replicas of the study objects in the form of point clouds. Besides, their output is raw and unstructured, and the transition to intelligible and semantic 3D representations is still a scarcely automated and time-consuming process requiring considerable human intervention. More refined methods for 3D data interpretation of heritage point clouds are therefore sought after. In tackling these issues, the proposed approach relies on (i) the application of machine learning techniques to semantically label 3D heritage data by identification of relevant geometric, radiometric and intensity features, and (ii) the use of the annotated data to streamline the construction of Heritage-Building Information Modeling (H-BIM) systems, where purely geometric information derived from surveying is associated with semantic descriptors on heritage documentation and management. The “Grand-Ducal Cloister” dataset, related to the emblematic case study of the Pisa Charterhouse, is discussed.; This work presents a semi-automatic approach to the 3D reconstruction of Heritage-Building Information Models from point clouds based on machine learning techniques. The use of digital information systems leveraging on three-dimensional (3D) representations in architectural heritage documentation and analysis is ever increasing. For the creation of such repositories, reality-based surveying techniques, such as photogrammetry and laser scanning, allow the fast collection of reliable digital replicas of the study objects in the form of point clouds. Besides, their output is raw and unstructured, and the transition to intelligible and semantic 3D representations is still a scarcely automated and time-consuming process requiring considerable human intervention. More refined methods for 3D data interpretation of heritage point clouds are therefore sought after. In tackling these issues, the proposed approach relies on (i) the application of machine learning techniques to semantically label 3D heritage data by identification of relevant geometric, radiometric and intensity features, and (ii) the use of the annotated data to streamline the construction of Heritage-Building Information Modeling (H-BIM) systems, where purely geometric information derived from surveying is associated with semantic descriptors on heritage documentation and management. The “Grand-Ducal Cloister” dataset, related to the emblematic case study of the Pisa Charterhouse, is discussed.

The digitization of Cultural Heritage paves the way for new approaches to surveying and restitution of historical sites. With a view to the management of integrated programs of documentation and conservation, the research is now focusing on the creation of information systems where to link the digital representation of a building to semantic knowledge. With reference to the emblematic case study of the Calci Charterhouse, also known as Pisa Charterhouse, this contribution illustrates an approach to be followed in the transition from 3D survey information, derived from laser scanner and photogrammetric techniques, to the creation of semantically enriched 3D models. The proposed approach is based on the recognition -segmentation and classification- of elements on the original raw point cloud, and on the manual mapping of NURBS elements on it. For this shape recognition process, reference to architectural treatises and vocabularies of classical architecture is a key step. The created building components are finally imported in a H-BIM environment, where they are enriched with semantic information related to historical knowledge, documentary sources and restoration activities.

This contribution proposes a methodological approach for the transfer of annotations between orthophotos and 3D digital heritage models, relying on a mesh-based/point-based representation. The workflow leverages on the exploitation of 2D/3D projective relations and on the identification, propagation, modelling and tiling of virtual models of architectural heritage. Referring to the significant case study of Pisa Cathedral, the method is tested to ensure an informative continuum between 2D medias and 3D representations, in terms of morphology, geometry and semantic enrichment. At first, a high resolution ortho-photo is created to support studies related to conservation and restoration, e.g. to highlight degradation patterns and materials as well as to distinguish cracks, frescoed surfaces, decorations. Then, the information is translated from the 2D support to a virtual 3D mockup: this step is essential to ensure a complete understanding of the architectural heritage object, that can thus be studied in its entirety, considering its morphological complexities. The proposed approach provides a more effective system for the transfer and exchange of semantic information from high-resolution orthophotos to semantically rich 3D models, that can be fundamental even in view of the construction of Heritage-Building Information Modeling (H-BIM) environments.

Cultural heritage studies often require the analysis of buildings that have undergone several changes and alterations during their lifetime. This often implies the loss of architectural elements or the construction of new elements, which both change the characteristics of the former buildings. The recovery of lost elements or structures through virtual reconstruction is of paramount importance in both scientific and cultural applications. Novel procedures in surveying and photogrammetric processing including historical photogrammetry and historical terrestrial laser scanning offer powerful tools that enable the extraction of geometric information from historical documentation such as archival images. This paper presents the integration of a metric 3D model with information present in archival surveys of lost architectural volumes. The methodology implies the availability of historical plans representing the survey object at scales consistent with UAV surveys and featuring shared elements. The methodology used to frame these plans in the reference system of the UAV survey for an open source GIS environment is also described as well as the accuracy checks. Finally, the procedure followed for the virtual reconstruction of the Fortezza in a BIM environment, which produced a model derived from the integration of historic and current data, is described.

Benchmark sessions are an efficient tool for sharing best practices as regards surveying, data processing and presentation of results within a scientific community. The Italian Society of Photogrammetry and Topography (SIFET) introduced this particular type of session in its annual national conference starting in 2016. This article reports some considerations that emerged from the positive experience of the 2019 benchmark sessions held in Venice on the underwater photogrammetry topic. In addition to some interesting results, the advantages of analyzing the results obtained by different and heterogeneous groups, as regards training and software and hardware tools exploited, starting from the same dataset are highlighted.

Research in the field of Cultural Heritage is increasingly moving towards the creation of digital information systems, in which the geometric representation of an artifact is linked to some external information, through meaningful tags. The process of attributing additional and structured information to various elements in a given digital model is customarily identified with the term semantic annotation; the added contextual information is associated, for instance, to analysis and conservation terms. Starting from the existing literature, aim of this work is to discuss how semantic annotations are used, in digital architectural heritage models, to link the geometrical representation of an artefact with knowledge-related information. Most consolidated methods -such as traditional mapping on 2D media, are compared with more recent approaches making the most of 3D representation. Reference is made, in particular, to Heritage-BIM techniques and to collaborative reality-based platforms, such as Aïoli (http://aioli.cloud). Potentialities and limits of the different solutions proposed in literature are critically discussed, also addressing future research challenges in Cultural Heritage application fields.

In the last decades, surveying methodologies related to Geomatics applications in the Cultural Heritage field have undergone a constant evolution. The first innovation has surely been the development, in the 1990s, of laser scanning systems. These are able to survey the coordinates of millions of points of architectural objects with sub-centimeter precision and high density. The second breakthrough, starting from the 2000s, is the “second youth” of photogrammetry methodologies. The “new photogrammetry” yielded tools and methodologies able to provide low-cost 3-D models, featuring photo-quality textures, suitable for very high scales reconstructions. Although both methodologies are fairly consolidated, one interesting research topic is the integration of the different methodologies aimed at optimizing results as regards both logistics-costs and attainable precision levels. The paper focuses on the latter topic, showing the methodological approach followed for the outer face restitution for the North transect of the Pisa Cathedral at 1:20 scale, as requested by the staff in charge of maintenance and restoration. In detail, the precision problems for the least accessible parts and for the transitions between orthogonal and parallel surfaces, relative to the average direction of the camera axis, are discussed. Finally, the processing methodology used for restitution at the same scale of the development of curved masonry sections, is presented. While compiling these documents for architecture study and documentation, attained geometric precision and texture resolution are checked, with a particular focus on how segmenting model sections with primitive surfaces can improve these parameters, and as a consequence also the final restitution.

Over the last years, the area of conservation and enhancement of cultural heritage has benefited from new surveying methodologies. In particular, laser scanners and the latest evolutions in digital photogrammetry and processing software based on structure from motion and multi-view stereo algorithms allowed to achieve 3D models of the status quo whose features include precision suitable for restoration scales and high-quality textures. Besides methodological and technical issues, another key requirement for any intervention on this kind of buildings is their full, in-depth knowledge, which includes building design, modifications’ timeline, current conditions, present-day and historical causes of degradation etc. In this view, surveys are a valuable asset for the investigation of historical sources. The present work investigates historical photographic sources, focusing on the possibility of orientation by means of photogrammetry techniques, which provides an additional texture layer as a support tool for historical analysis. The paper displays a case study featuring the availability of a reference survey, which allows validation of the results, and two other cases highlighting the importance of this kind of documents to restoring teams.

"The paper concerns the logistics activities related to perishable products. Perishable products are delivered from the production site to a warehouse by refrigerated truck. Perishable products are accepted or not at the warehouse entrance, according to their detected quality levels; if accepted, they are stored in the warehouse in suitable environmental conditions. Finally, they are delivered by refrigerated truck to the destination. Human errors affect these activities. Perishable products have to be delivered in a suitable quality level to the destination. Because of human errors, sometime products arrive in an unsuitable quality level and therefore, there is a loss for the company. RFID technologies, integrated with time temperature indicators (TTI), allow a prompt detection of abnormal quality loss and the prompt actuation of mitigation actions. In order to evaluate the benefits of different RFID-TTI implementation set-ups, the study defines a methodology that measures the risk of monetary losses. The method is applied to a case study and the results are presented."

The paper addresses the quality issues concerning the logistic processes carried out by air cargo handlers and proposes a methodology that allows assessing the performances resulting from different RFID implementation set-ups within an air cargo handler’s warehouse. The performances have been assessed in terms of benefits related to the informatization, i.e. the timely put in place of rework and mitigation measures in the case of human error detection, in order to reduce the severity of the mistakes’ consequences. This problem has been faced by means of a risk analysis. A simulator has been calibrated and validated with the support of expert operators in the field of air cargo logistics. Probabilistic Risk Assessment allowed us to solve the forecasting problem connected to human activities with hazardous characteristics. We applied the proposed method to a real case of study and it allowed us quantifying an average monetary loss for the current scenario (without any RFID implementation) close to the one currently experienced by the air cargo handling company. In the case of different RFID implementation set-ups (intermediate and full), the assessed values are coherent with the company’s operator expectations. In particular, we observed a big improvement for the intermediate RFID implementation set-up, whereas a full RFID set-up seems not worth to be implemented in accordance with the company’s managers’ anticipations.

Sometimes it is difficult to represent “on paper" the existing reality of architectonic elements, depending on the complexity of his geometry, but not only in cases with complex geometries: non-relief surfaces, can need a “special planar format” for its graphical representation. Nowadays, there are a lot of methods to obtain tridimensional recovery of our Cultural Heritage with different ranges of the relationship accuracy / costs, even getting high accuracy using “low-cost” recovery methods as digital photogrammetry, which allow us easily to obtain a graphical representation “on paper”: ortho-images of different points of view. This can be useful for many purposes but, for others, an orthographic projection is not really very interesting. In non-site restoration tasks of frescoed vaults, a “planar format” representation in needed to see in true magnitude the paintings represented on the intrados vault, because of the general methodology used: gluing the fresco on a fabric, removing the fresco-fabric from the support, moving to laboratory, removing the fresco from the fabric, restoring the fresco, gluing back the restored fresco on another fabric, laying the restored fresco on the original location and removing the fabric. Because of this, many times, an unfolded model is needed, in a similar way a cylinder or cone can be unfolded, but in this case with a texture included: UV unwrapping. Unfold and fold-back processes, can be especially interesting in restoration field of frescoed vaults and domes at: chromatic recovery of paintings, reconstruction of partially missed geometries, transference of paintings on surfaces, etc.

The present contribution illustrates the results obtained to date on an ongoing research study of the mechanical response and load capacity of the dome of Pisa Cathedral. A well-known feature of structural modelling is that it requires reliable data on the actual shape and material properties of the structure in question. Moreover, a comprehensive account of relevant historical and architectural aspects is needed as well. Hence, the starting point of our research work consisted of high-density, precision surveys. Both range-based (laser scanning) and image-based (3D photogrammetry) survey methodologies have been used to obtain different structural models. Furthermore, a set of experimental tests has been performed to evaluate the constituent masonry's properties. From the mechanical point of view, the research has focused mainly on structural analysis of the dome subject to vertical dead loads. The dome's mechanical behaviour is described by means of both analytical and numerical analyses. The results obtained via these different methods are discussed.

The paper offers a reflection on current methodologies for 3-D surveying aimed at the generation of geometrically consistent models provided with realistic textures for fruition in virtual reality environments. In particular, the possible use of these tools is discussed for both technical-scientific applications and devising virtual immersive experiences by means of gaming engines. The reflections are accompanied by a case study involving a historical site in Livorno, the Fortezza Vecchia, with particular focus on the North gallery, a section where public access is prohibited.

Management of disaster scenarios requires applying emergency procedures ensuring maximum safety and protection for field operators. Actual conditions of disaster sites are labelled as “Triple-D: Dull, Dusty, Dangerous” areas. It is well known that in this kind of areas and situations remote surveying systems are at their very best effective, and among these UAVs currently are an effective and performing field tool. Indoor spaces are a particularly complex scenario for this kind of surveys. In this case, technological advances currently offer micro-UAV systems, featuring 360° protective cages, which are able to collect video streams while flying in very tight spaces. Such cases require manual control of the vehicle, with the operator piloting the aircraft without prior knowledge of the status quo of the survey object and therefore without prior planning of flight paths. A possible benefit in terms of knowledge of the survey object could lay in the creation of a 3D model based on images extracted by video streams; to date, widely tested methods and techniques are available for processing UAV-borne video streams to obtain such models. Anyway, the protective cage and the need to use, in these operating conditions, wide-angle lenses presents some issues linked to ever-changing image framing, due to the presence of the cage wires on the field of view. The present work focused on this issue. Using this type of UAVs, video streams have been collected in different environments, both indoors and outdoors, testing several procedures for photogrammetric processing in order to assess the ability to create 3D models. These have been tested for reliability based on data collection conditions, also assessing the level of automation and speed attainable in post-processing. The present paper describes the different tests carried out and the related results.

In the restoration of the frescoed vaults it is not only important to know the geometric shape of the painted surface, but it is essential to document its chromatic characterization and conservation status. The new techniques of range-based and image-based modelling, each with its limitations and advantages, offer a wide range of methods to obtain the geometric shape. In fact, several studies widely document that laser scanning enable obtaining three-dimensional models with high morphological precision. However, the quality level of the colour obtained with built-in laser scanner cameras is not comparable to that obtained for the shape. It is possible to improve the texture quality by means of a dedicated photographic campaign. This procedure, however, requires to calculate the external orientation of each image identifying the control points on it and on the model through a costly step of post processing. With image-based modelling techniques it is possible to obtain models that maintain the colour quality of the original images, but with variable geometric precision, locally lower than the laser scanning model. This paper presents a methodology that uses the camera external orientation parameters calculated by image based modelling techniques to project the same image on the model obtained from the laser scan. This methodology is tested on an Italian mirror (a schifo) frescoed vault. In the paper the different models, the analysis of precision and the efficiency evaluation of proposed methodology are presented.

The evolution of Structure from Motion (SfM) techniques and their integration with the established procedures of classic stereoscopic photogrammetric survey have provided a very effective tool for the production of three-dimensional textured models. Such models are not only aesthetically pleasing but can also contain metric information, the quality of which depends on both survey type and applied processing methodologies. An open research topic in this area refers to checking attainable accuracy levels. The knowledge of such accuracy is essential, especially in the integration of models obtained through SfM with other models derived from different sensors or methods (laser scanning, classic photogrammetry ...). Accuracy checks may be conducted by either comparing SfM models against a reference one or measuring the deviation of control points identified on models and measured with classic topographic instrumentation and methodologies. This paper presents an analysis of attainable accuracy levels, according to different approaches of survey and data processing. For this purpose, a survey of the Church of San Miniato in Marcianella (Pisa, Italy), has been used. The dataset is an integration of laser scanning with terrestrial and UAV-borne photogrammetric surveys; in addition, a high precision topographic network was established for the specific purpose. In particular, laser scanning has been used for the interior and the exterior of the church, with the exclusion of the roof, while UAVs have been used for the photogrammetric survey of both roof, with horizontal strips, and façade, with vertical strips.

This paper presents an original methodology for planar development of a frescoed dome with an oval plan. Input data include a rigorous geometric survey, performed with a laser scanner, and a photogrammetry campaign, which associates a high-quality photographic texture to the 3D model. Therefore, the main topics include the development of geometry and, contextually, of the associated textures. In order to overcome the inability to directly develop the surface, an orthographic azimuthal projection is used. Starting from a prerequisite study of building methodology, the dome is divided into sectors and bands, each linked with the maximum acceptable deformations and the actual geometric discontinuities detectable by the analysis of Gaussian curvature. Upon definition of the development model, a custom automation script has been devised for geometry projection. This effectively generates a (u,v) map, associated to the model, which is used for model texturing and provides the planar development of the fresco.

Over the last decade, we have seen the widespread use of digital survey technologies that have made the three-dimensional (3D) metric survey within reach of all. In the past, lengthy training was needed to use total stations and classical photogrammetry. Today, laser scanning and “new photogrammetry” allow operators with little training to produce 3D models with high spatial density in real time. These systems have therefore made 3D metric survey available to a wide audience of professionals, and have also allowed surveys to be performed with little economic investment in instrumentation. Although this evolution in survey methodologies has certainly brought great benefits, the use of these methods by operators with limited training poses some risk. The proliferation of imprecise processed 3D data, however, constitutes a digital archive of documentation which, by its nature, should be semi-automatically integrated. Issues related to reference systems, scale of representation, accuracy, and related metadata therefore become highly relevant. This paper aims to describe, by means of several case studies, the laser scanner and “new photogrammetry” survey methodologies in light of the aforementioned issues. In addition, the use of “new photogrammetry” in combination with UAV systems will be presented. The integration and miniaturization of positioning systems, attitude measuring systems, and survey instruments (cameras, laser scanners, thermal and multispectral cameras, etc.) allow, by drone flight, the creation of 3D surveys, something that was impossible several years ago without a substantial budget for the use of conventional aircraft.

11 years ago, on 28 December 2005, was launched the Europe’s very first navigation satellite, GIOVE-A (Galileo In-Orbit Validation Element-A), thus starting the deployment of Galileo, the EU’s own global satellite navigation system. The deployment phase of Galileo suffered of many difficulties and delays but recently the Programme has been accelerated and, in the last months, the pace of deploying Europe’s own satellite navigation system continued to increase with the launch of the 18th Galileo satellite, on 17 November 2016. It is expected that the system will be fully operational by 2020, with actual implementation costs in the range of 5.23 billion of euros and 7 billion foreseen till 2020 for EGNOS e Galileo Projects. The excellent performances of Galileo satellites, as measured on the ground, “allows Europe to join the club of the worldwide providers of satellite navigation services”. Galileo will be integrated by EGNOS (European Geostationary Navigation Overlay service). Consisting of three geostationary satellites and a network of ground stations, EGNOS achieves its aim by transmitting a signal containing information on the reliability and accuracy of the positioning signals sent out by GPS. It allows users, in Europe and beyond, to determine their position to within 1.5 m (1σ). Since the first signals became available to users, demonstrations have shown the usefulness of EGNOS services in every type of kinematic application, in the aerial, maritime and terrestrial domain. As part of ‘GIANT’ (GNSS Introduction in the AviatioN sector), tests have proved the benefits of EGNOS when landing at airports with fewer aids or when helicopters make emergency landings. The integrity data provided by EGNOS is particularly suited for applications driven by stringent safety constraints during critical navigation phases such as landing aircraft, manoeuvring ships in narrow channels, and tracking the precise locations of trains. Actually many applications are based on EGNOS, and the Open Service (OS), available since October 2009, is widely used in the agricultural world, where it has proved valuable for reducing the use of fertilisers, thus helping to protect the environment. The accuracy of the Open Service has also proved useful to guide blind people in the city via mobile phones—like car drivers using GPS. Towards the certification of the Safety of Life service, many tests have been performed in the aviation, maritime and rail sectors. Mapping of fixed assets, controlling mining machinery and other professional uses are potential applications that could benefit from the EGNOS Commercial Data. Demonstrations showing the potential of EGNOS have been performed in many other sectors and many applications are just waiting to be thought of, such as for rail, road and maritime users. The European Commission (EC) estimates that 6–7% of European GDP (Gross Domestic Product)—around 800 billion by value—is already dependent on satellite navigation. Any GNSS device available on the marked is able to receive GPS, GLONASS and EGNOS signals and globally 40% of GNSS receivers are ready to receive Galileo signals. Multi-constellation services and receivers are used by millions of persons in the world, being part of their daily life, towards a future where geo-localisation of persons and things will become essential for safety and well-being. In this paper the current trend and benefits of multi-constellation services and receivers as well as innovative kinematic research applications, carried out by GeoSNav Lab, Department of Engineering and Architecture, University of Trieste, research team, using multi-constellation receivers, are presented.

Since the 1990s, with the availability of satellite positioning techniques, enabling to determine three-dimensional point coordinates in a global reference system with topographic accuracy, several applications dedicated to mapping of the territory by means of mobile geo-referenced sensors have steadily been developed. This paper discusses the experiences gained in this field at the University of Pisa—Laboratory of Topography over more than twenty years of experimental work. These activities, often conducted in cooperation with the University of Trieste and in particular with Professor Giorgio Manzoni, have always featured a multidisciplinary approach. Different types of sensors have been installed, at first in land-based vehicles and currently on unmanned aerial systems: GPSs, GNSSs and INSs, carbon monoxide and particulate matter measuring systems, single- and multiple-axis laser scanners, industrial and photography cameras. Use of these sensors, besides drafting and testing maps of the territory in several areas (cartography, road cadastre, pollution monitoring, city modelling …), allowed to keep track of the development of instrumentation and methods of kinematic positioning.

Fire Departments feature specialized teams for Urban Search And Rescue (USAR) activities, operating in case of disasters and in collapse contexts, where the actual situation no longer coincides with any previous survey. In this context, current UAV-borne photogrammetry may offer very effective methods, enabling achievement of to-date knowledge of the status quo. Their effectiveness in these contexts is due to the ability of drones to operate in triple-D areas (Dull, Dusty, Dangerous) and to the remote sensing features inherent in photogrammetry.

Territorial management requires the most possible up-to-date mapping support of the status quo. Regional scale cartography update cycle is in the medium term (10 to 15 years): therefore, in the intervening time between updates relevant Authorities must provide timely updates for new works or territorial changes. Required surveys can exploit several technologies: ground-based GPS, Terrestrial Laser Scanning (TLS), traditional topography, or, in the case of wider areas, airborne photogrammetry or laser scanning. In recent years UAV-based photogrammetry is becoming increasingly widespread as a versatile, low-cost surveying system for small to medium areas. This surveying methodology was used to generate, in order, a dense point cloud, a high resolution Digital Surface Model (DSM) and an orthophotograph of a newly built marina by the mouth of the Arno river in Pisa, Italy, which is not yet included in cartography. Surveying activities took place while the construction site was in operation. Case study issues surfaced in the course of the survey are presented and discussed, suggesting ‘good practice’ rules which, if followed in the survey planning step, can lessen unwanted effects due to criticalities. Besides, results of quality analysis of orthophotographs generated by UAV-borne images are also presented. Such results are discussed in view of a possible use of orthophotographs in updating medium- to large-scale cartography and checked against existing blueprints.

The historical architectural heritage may be considered as the product of a complex system of interaction between several factors - cultural, socio-economic, technical, aesthetic etc. The restoration and conservation of this important heritage, therefore, requires necessarily a multidisciplinary approach, both in the preliminary phase of knowledge and in the operative one, strictly connected to the first, regarding the development of the restoration works in all their steps, from the project to the realization. The historical-critical analysis of bibliographic, archival and iconographic sources, together with the architectural survey, aims at interpreting all the events that, from the initial project to all the eventual phases of transformation, have lead the monument in its current state. This is therefore a multi-temporal and multi-spatial study in which geomatics gives an innovative contribution for its capability of gathering, storing, processing, and delivering different levels of spatially referenced information. The current techniques of architectural survey, supported by specific methodological skills, are therefore not limited to a mere mathematical-geometrical description of the historical building, but are useful also for many other purposes, such as formal-linguistic analysis, interpretation of the historical phases of transformation, description of the state of degradation/conservation etc. In this interdisciplinary perspective, photogrammetry and laser scanner represent the two main techniques, as they offer the greatest potential of performing integrated surveys. In the last decades, we have witnessed the growth and development of these 3D-survey techniques as alternative or complementary tools to the traditional ones. In particular, in the field of architectural restoration, these techniques have made significant improvements not only in terms of measure precision or reduction of time for survey operations, but also for the possibility to represent and visualize the historical building in its context. These modern techniques of survey, based on the creation of point clouds, are now widely used both in the study of a building and for the thorough description of architectural details and decorations. This paper aims at describing the methodological approach and the results of the 3D survey of the Chapel of St. Agata in Pisa, aimed at its restoration. For the development of a restoration project, the survey drawings must represent not only the geometry of a building, but also the materials and the level of degradation. So, we chose to use both the laser scanner - which guarantees uniformity of the geometric survey precision - and a 3D image-based modelling. The combined use of these two techniques, supported by a total station survey, has produced two point clouds in the same reference system, and allowed the determination of the external orientation parameters of the photographic images. Since these parameters are known, it was possible to texturize the laser scanner model with high quality images. The adopted methodology, as expected, gave back metrically correct and graphically high-quality drawings. The level of detail of the survey, and consequently of the final drawings, has been previously defined for the identification of all the elements required for the analysis of the current state, such as the clear identification and position of all the degradation phenomena, materials and decorative elements such as some fragmented and heavily damaged frescoes.

This paper aims to illustrate the preliminary results of a research project on the dome of Pisa Cathedral (Italy). The final objective of the present research is to achieve a deep understanding of the structural behaviour of the dome, through a detailed knowledge of its geometry and constituent materials, and by taking into account historical and architectural aspects as well. A reliable survey of the dome is the essential starting point for any further investigation and adequate structural modelling. Examination of the status quo on the surveys of the Cathedral dome shows that a detailed survey suitable for structural analysis is in fact lacking. For this reason, high-density and high-precision surveys have been planned, by considering that a different survey output is needed, according both to the type of structural model chosen and purposes to be achieved. Thus, both range-based (laser scanning) and image-based (3D Photogrammetry) survey methodologies have been used. This contribution introduces the first results concerning the shape of the dome derived from surveys. Furthermore, a comparison is made between such survey outputs and those available in the literature.