This paper explores the application of space–time cubes (S–T cubes) and geospatial artificial intelligence (GeoAI) for monitoring vertical settlements in structures. Although S–T cubes are not commonly employed in this type of structural analysis, they enable the storage and visualization of multi-temporal monitoring data, offering an effective framework to represent differential settlement over time within a defined spatial domain, including at the scale of individual structural elements. The study further integrates GeoAI techniques for predictive analysis aimed at detecting discontinuities, leveraging the temporal datasets organized within S–T cubes. We employ an index that combines accuracy across multiple prediction steps with least-squares statistics of adjusted data. This provides users with a rapid diagnostic to verify the effectiveness of forecasts before deeper analysis. Results from three datasets—each representing a monitoring project with distinct characteristics—demonstrate that machine-learning-based forecasts remain reliable for at least three prediction steps ahead. This level of consistency is sufficient to support the detection of discontinuities in new monitoring campaigns, with a precision on the order of ± 0.2–0.3 mm.

Digital technologies have significantly advanced documentation, management, and dissemination of Cultural Heritage (CH) through reality capture, Heritage Building Information Modelling (HBIM), and Extended Reality (XR). However, the digitisation of large and historically stratified heritage sites still relies on fragmented workflows that compromise interoperability and interrupt the continuity of geometric and semantic information throughout the heritage lifecycle. This paper proposes and validates a platform-independent, ecosystem-based methodology integrating multi-scale reality capture, hybrid Scan-to-HBIM modelling, semantic information management, interoperability, and XR within a continuous digital workflow. The methodology was validated through the large-scale digitisation of the Certosa di Pavia, where more than 1500 terrestrial laser scans, over 200,000 photographs, and approximately 50 billion points were acquired across a monumental complex covering nearly 331,000 m2. The proposed framework reconstructs irregular architectural geometries with millimetre-scale accuracy (σ = 0.005 m) while preserving geometric reliability, semantic consistency, and information traceability across point-cloud processing, HBIM environments, Common Data Environments (CDEs), and XR applications. The results demonstrate that the effective digitisation of complex CH depends not only on the accuracy of individual technologies but also on their coordinated integration within interoperable digital ecosystems. The proposed methodology provides a transferable framework for preserving knowledge continuity throughout the heritage lifecycle, enabling HBIM to evolve from a geometric representation into a dynamic knowledge environment supporting conservation, management, research, education, and public dissemination.

Orthophotos offer a distortion-free and high-resolution depiction of architectural and mechanical elements, serving critical functions in reverse engineering, defect detection, and condition assessment. Recent advancements in low-cost sensors have made them increasingly popular for orthophoto generation due to their affordability and ease of use. However, reflective surfaces pose significant challenges in traditional photogrammetric workflows, leading to inaccuracies in feature matching and 3D reconstruction. This paper investigates the integration of Gaussian splatting into the orthophoto generation process as a solution to address these challenges. Gaussian splatting is particularly effective in handling irregular and sparse data, making it suitable for scenarios involving reflective surfaces. In this study, datasets containing reflective surfaces, such as metallic elements and urban environments, were used to evaluate the performance of Gaussian splatting compared to traditional photogrammetry workflow. Our findings indicate that Gaussian splatting effectively reduces artifacts caused by reflections while preserving geometric accuracy and critical detail in non-reflective areas. Additionally, this approach proves to be computationally efficient, making it ideal for low-cost sensor applications. Although limitations remain, such as smoothing effects that may reduce fine detail, the proposed methodology shows promise for improving orthophoto quality in complex environments.

In recent years, the field of reality-based 3D model generation has undergone a profound transformation, impacting disciplines such as preservation, archaeology, anthropology, and virtual museums by introducing concepts like virtual heritage and extended reality (XR). The integration of digital models and 3D survey data has become pivotal, enabling immersive experiences and providing unprecedented access to previously inaccessible archaeological sites. In 2022, the Soprintendenza Archeologia, Belle Arti e Paesaggio- Citt & agrave; Metropolitana di Bari embarked on a groundbreaking project to explore Lamalunga cave. This cave, housing a 172,000-130,000-year-old Neanderthal skeleton and 500 faunal remnants, became the focus of an interdisciplinary effort aimed at comprehensively documenting its morphological and typological details alongside the Neanderthal remains. Over a meticulous two-year period, the project meticulously recorded 28 previously undiscovered faunal remains using precise scanning, topographic surveying, and close-range photogrammetry. Central to this endeavor is the Science of Representation, employing advanced 3D modelling techniques such as NURBS algorithms and mesh retopology. These methods facilitated the creation of highly detailed and accurate digital replicas, capturing not only the cave's intricate physical features but also preserving the contextual integrity necessary for detailed analysis and interpretation of the archaeological findings. This study provides an overview of the digitisation process, examining both the capabilities and limitations of digital models for XR applications. By leveraging cutting- edge technology, this approach enhances preservation, accessibility, inclusivity, and global engagement with one of the world's most significant Neanderthal sites.

This paper introduces an integrated approach utilizing ground data consists of videos captured with a 360° (spherical) camera and aerial data acquired with a UAV equipped with a RTK GNSS module to reconstruct a portion of a small-town city center and/or a cultural heritage site. Previous research has demonstrated that image blocks oriented with RTK data on camera position can reach centimeter accuracies and can be efficiently used to reconstruct large areas and single monuments. However, some areas like porches, narrow passages and streets cannot be properly reconstructed from an aerial point of view. Conversely, ground-based 360° images offer detailed insights into the terrain and features that may be obscured from an aerial perspective. Integration of those two points of view can increase spatial resolution and coverage for 3D reconstruction. Indeed, the UAV captures large-scale features and topography, while ground-based 360° images focus on intricate details and ground-level characteristics. The possibility to exploit GNSS data acquired by UAV may also be used for GNSS-assisted image orientation with the aim of reducing or even avoiding, in specific situations, the need for GCPs. The paper explores practical applications of such data integration in the cultural heritage domain demonstrating the efficacy of the integrated approach in scenarios with complex architectures and inaccessible areas.

The system described in the paper is a prototype of a novel 360 degrees borescope for digital documentation in confined spaces. The method was designed for both 360 degrees inspections and photogrammetric applications in very tight and narrow spaces (even less than 30-40 cm), in which traditional digital documentation is usually impossible. The prototype is based on a panoramic camera and an integrated lighting LED system to allow for efficient image acquisition in small chambers where other documentation methods (like laser scanning and traditional photogrammetry) are not feasible due to space restrictions. Laboratory tests have demonstrated the system's capability to achieve metric precision of approximately +/- 1-2 cm, making it a reliable tool for confined-space documentation. By offering high-resolution imaging and the ability to generate 3D models with minimal intervention, this system represents a significant step forward in the field of confined-space documentation, with applications ranging from industrial inspections to heritage preservation.

Abstract. Photogrammetric applications using 360° images are becoming more and more popular in different fields, such as cultural heritage documentation of narrow spaces; civil, architectural, and environmental projects like tunnel surveying; mapping of urban city centres, etc. The popularity of 360° photogrammetry relates to the high productivity of the acquisition phase, giving the opportunity to capture the entire scene around the user in a relatively short time. On the other hand, the photogrammetric workflow needs ground control points (GCPs), well distributed over the survey area, to georeference the produced 3D data. Placing, measuring on-field, and identifying GCP on images is time-consuming and sometimes even not feasible due to environmental conditions. While effective solutions exist for UAV-based projects, direct georeferencing and GNSS assisted photogrammetry is still not fully exploited for ground-based acquisitions. This paper aims at presenting a solution coupling 360° images and high-precision GNSS systems for direct georeferencing of outdoor projects without the need for manually measuring GCPs. Three different acquisition modes for 360° images and GNSS data are presented, and orientation results are compared with manually measured Check Points.

Abstract. Digitization of complex Cultural Heritage sites requires the integration of several strategies to achieve a comprehensive description of the site. This is the case of the digitization project of the Appian Way in Rome involving a section of 12 km from Capo di Bove to Frattocchie under the superintendence of the Parco Archeologico dell’Appia Antica. This paper presents some first results of the project with a specific focus on the acquisition of the primary data needed for the further steps of the project. In particular, the paper discusses the integration of different sensors such as lidar-based Mobile Mapping Systems, spheric (360°) cameras and digital (frame) calibrated cameras, for the reconstruction of point clouds to be used as input data for the digitization process. A specific attention is paid both on acquisition speed and to accuracy of the obtained results. The paper presents also some results showing the transformation of the acquired data into a GIS system to be used as a support tool for decision making of the public administration.

This paper aims at presenting the recording and modelling work developed in the framework of restoration and conservation activities for the Basilica di San Giacomo in Como, Italy, whose construction started in the 11th century. The project started in 2022 and involved the application of the Historical Building Information Model (HBIM) methodology through a Scan-to-BIM approach was assessed. High-detailed 3D survey techniques were used to acquire the specific shape of the church and annexed buildings. Then, through different modelling strategies, the HBIM environment allowed the representation of all the architectural elements. The purpose of this model is to have essential support to plan the restoration activities and to give the different experts involved a single three-dimensional tool for managing all the information during the development of the construction works. The possibility to update the model over time with geometric and non-geometric information will provide a powerful tool also for other future activities, such as the installation of a monitoring system that could reveal the displacements of bearing elements of the church.

From Rome to Benevento, the Appian Way (Via Appia Antica) was born as a military road, 'Regina Viarum'. In 312 b.C., consul Appio Claudio extended the infrastructure for 132 miles to Capua. Many transformations and integration occurred across the centuries, resulting in a unique multi-stratified world heritage (landscape, architecture, archaeological remains and tombs along the military way). In the 19th century, Luigi Canina conceived the Appian Way as an outdoor museum, realizing a first state-own section along the 12km here surveyed and described. This year, the Ministry of Culture (MIC) has launched the UNESCO nomination for the road. The article discusses aspects of the mass digitization undertaken by the Parco Archeologico dell'Appia Antica (PAAA, the Archaeological Park of the Appian Way). The aim is to build a Digital Twin of the infrastructure supporting knowledge enhancement, preservation, design, communication and fruition. A virtual space where digital technologies and eXtended Reality are the digital arms of the contemporary Vitruvian humanistic mission and vision of the PAAA Appian Way as a source of wealth and healthiness for all the users and visitors.

This paper illustrates and discusses a novel method for the digital documentation of human remains in narrow spaces. A 360° borescope prototype made up of a panoramic camera and a lighting LED system was designed and assembled to acquire data in confined spaces for photogrammetric processing. A series of laboratory experiments were planned to assess the method’s validity. A modern concrete tunnel and a mock grave were surveyed using surveying instruments and a laser scanner, comparing the results with the borescope prototype. Then, data acquisition was moved to the field, i.e., in a real case study. Two burial vaults in a church containing human remains were selected and surveyed. The remains were accessible only from small breaches. The results show that using the 360° borescope is suitable for documenting narrow/confined spaces with minimum alteration of the scene. This result can be of interest for archaeological and forensic purposes, especially when the context is hardly accessible, with minimal intervention on the scene.

The Altamura Man and the paleontological remains are situated within a complex context encompassing logistical, geological, paleoenvironmental, and cultural perspectives. This context is exceptionally well-preserved but also fragile, requiring its preservation due to its unique nature. Unresolved inquiries exist in various disciplines, such as archaeology, biocultural studies, ecology, and geology, pertaining to karst formation, taphonomic dynamics, and the cultural and ecological context of the Neanderthal individual found in the cave. Interdisciplinary research was necessary to address these complex questions and understand the broader context of the Lamalunga Cave. Climate change also necessitated attention to preserving the cave's microclimate and monitoring potential biodegradation. Digital technologies, including photogrammetry and laser scanning, were crucial for monitoring and safeguarding the cave's cultural heritage. Digital representation, 3D modelling and Digital Twin were essential for managing the cave's intricacies, analysing its values, and enhancing visual communication. The management of the Lamalunga cave aimed to promote scientific interpretation, safeguard the cave, and provide tools for understanding, storytelling, and further investigation. It was essential to utilise available methodologies and technologies while avoiding destructive interventions. Contemporary technologies have revolutionised the archaeological and paleoanthropological domains, enabling remote study and preservation. Protecting and comprehending the cultural heritage of the cave is linked to its usability, which can be enhanced through digital documentation methodologies to inform visitors about the karst context and promote social and economic development.

The paper describes the origin and evolution of the monitoring system of the Duomo di Milano, which was installed during the 1960s. In that period, differential movements induced by the extraction of groundwater (among other factors) caused significant instability and risk of collapse of the monument. Today, the monitoring system is still operative. Instruments, techniques, and calculation procedures were continuously updated considering the continuity of the time series, resulting in a precious archive for structural health monitoring and conservation. The actual configuration of the monitoring system includes a large variety of both automatic and manual sensors, digital and mechanical, in real-time or with an established periodicity. Moreover, the monitoring system inside the cathedral still preserves continuity with the original measurements thanks to continuous maintenance carried out over time. The manuscript illustrates and discusses the original system as well as the updates related to activities that began more than half a century ago.

The “San Pietro al Monte Abbey project: a virtual tour for everyone” consists in the construction of a high-tech station that allows visitors with mobility limitations to be virtually accompanied by a guide to the Benedictine abbey of San Pietro al Monte along the ancient access route that can only be reached on foot with trekking equipment. The room with the virtual instrumentation is located in the Casa del Pellegrino in Civate (Lecco, Italy). It is a museum structure-based located in a media reception building. From its entrance, it is possible to see the final destination. The virtual tour preserves the dialogue between the environment, the monument, and the ‘virtual pilgrim’. By also acting as an information database, it enhances the use of the basilica of San Pietro al Monte even for visitors equipped with tablets who reach the building on foot. The virtual tour application has been developed with Unity3D. The interactive application has different virtual scenes with photos, 360 ^∘ videos, an external digital twin of the abbey, and some interesting internal digital twins of the most important monuments inside the abbey.

Constant monitoring activities of vertical settlement in the Duomo di Milano started during the ’60 when the rapid changes of the water table seriously affected the stability of the Cathedral. This paper describes the origin and evolution of the monitoring system, which is still operative thanks to continuous maintenance and technological advancements in measurement and processing methods. Nowadays, measurements are still acquired twice a year as a part of the traditional monitoring work, which is based on several other systems, including automatic and manual (mechanical) sensors and tools. A digital archive with more than 50 years of data is constantly updated, continuing a tradition that followed major restoration interventions and ordinary maintenance carried out by Veneranda Fabrica del Duomo di Milano (VFD). After more than half a century, the collaboration between VFD and Politecnico di Milano to monitor the Duomo is still active.

Video acquisition with 360° (spherical) cameras is becoming increasingly popular for the opportunity to capture the entire scene around the user in a relatively short time. The method can also be attractive for photogrammetric applications. As the overlap between consecutive frames is undoubtedly guaranteed, 3D models can be generated with an automated processing workflow. The paper illustrates the results achieved with 5k 360° videos captured with different Insta360 cameras. As the number of frames can become large, two complementary solutions are proposed to provide approximate initial exterior orientation parameters: the integration of the trajectory captured through GNSS, and the creation of an acquisition plan with a GIS-based application. The availability of approximated EO parameters provides a visibility map between the frames and reduces the computational cost during image matching. Experimental results demonstrate that such preliminary information is necessary for large datasets. Indeed, the photogrammetric processing of the entire dataset without the proposed preliminary EO parameters resulted in unreliable or incomplete orientation results.

This paper aims to analyze space-time cubes for visualizing and processing multi-temporal spatial monitoring data. The proposed case study is the Cathedral of Milan (Duomo di Milano), which has a set of monitoring time series spanning more than half a century. Differential vertical movements are periodically measured for the cathedral columns, constituting a continuous spatio-temporal dataset for structural health monitoring. More specifically, the space time pattern mining toolbox in ArcGIS Pro was used to (i) create a space-time cube and (ii) perform advanced analysis using the monitoring dataset, including time-series clustering and forecasting operations.

At Annone di Brianza (Italy) in the Church of St. George, it is possible to admire the “ANCONA DELLA PASSIONE" (altarpiece of the Passion), an altarpiece painted and gilded carved wood cabinets. The great altarpiece adorned the right side chapel of Saint John the Baptist, whose construction dates back to the first half of the century XVI at the behest of Annoni, one of the most authoritative families of Milan of the sixteenth and seventeenth century. Since 2019 the altarpiece has been protected inside a special room in order to avoid damage caused by the temperature and humidity. Access to this room is not allowed to people who visited the church. In order to allow the user to admire and explore each minimal detail of the polyptych altarpiece a totem has been designed and it’s located just outside of the special room. The totem in fact is composed of a 32 in. touch screen with a PC embedded and the Virtual tour application. The Virtual tour application has been developed with Unity3D. The interactive application has different virtual scenes with photos, videos, an external digital twin of the polyptych with both, open and closed doors.

2020 meant the loss of 41.5 million visitors for Italian museums, monuments and archaeological sites. The regions that drive tourism and the Italian museum paid the price in terms of visitors and income. In this context, virtual museums have been taking on new forms of interaction, communication and sharing of information, overshadowing traditional applications based on sharing collections through static images or simple panoramas. Virtual Reality (VR) and Augmented Reality (AR) provide the end-user with more innovative learning with the latest technological advances and digital tools. Thanks to the integration of the latest 3D modelling and digital survey techniques with the Visual Programming Language (VPL) and eXteded Reality (XR) development platforms, the authors propose a scan-to-BIM-to-XR method based on different forms of architectural representation, digital survey (terrestrial and aerial) and building archaeology able to transmit the tangible and intangible values of the different types of architectural artefacts, from the large scale (building and its urban context), medium (art collections, sculptures, museum itineraries) up to the small scale (building archaeology) of one of the most important historical buildings in the city of Rome.

This paper describes the case study of the damaged church of St. Francesco in the hamlet of Arquata del Tronto (Italy) that was struck by the earthquake in 2016. The municipality commissioned the research to support the preliminary design of the preservation plan. The first digitisation level has been started from the richness of surveying data acquired from static and dynamic terrestrial laser scanning (TLS), and photogrammetry, overcoming challenging constraints due to the scaffolding covering the surfaces. The geometric survey allowed authors to acquire massively geometric and material information supporting the three-dimensional (3D) volume stratigraphic and the creation of the Heritage Building Information Modelling (HBIM). The paper proposes a shift from the Geographic Information System (GIS)-based analysis of the materials toward spatial HBIM management. Building Archaeology is turned into HBIM 3D volume stratigraphy, overcoming the bidimensional (2D) surface mapping, in favour of a 3D understanding of direct and indirect sources. Material mapping is added to HBIM 3D volume stratigraphy, and each stratigraphic unit (SU) has its proprieties. The 3D volume stratigraphic database has been designed to collect the data on the unit detection at three levels (direct sources data collection, indirect data documentation, the relation among the BIM object elements). A common data environment (CDE) has been set up to share the 3D volume informative models that can be accessed, and all the information gathered. The knowledge transfer using the eXtended reality (XR) has been devoted to the citizen and tourist fruition, enhancing the comprehension of difficult concepts like the SUs to support a better critical 3D reconstruction. It includes the phases of construction across time-lapse documentation that validates related information within the building archaeology informative models leaving spaces to the uncertainty and documenting the relationship established so far thanks to the direct and indirect sources. The result obtained is a live digital twin that can be continuously updated, which justifies the costs and time demanding of HBIM despite 2D drawings.Highlights: • 3D survey and scan-to-HBIM process for the creation of a digital twin were oriented to the preliminary design of the preservation plan of the church of St. Francesco in Arquata del Tronto (Italy). • Stratigraphy is investigated and oriented towards a digitisation process to share different levels of knowledge through new forms of digital-sharing such as Common Data Environment (CDE) and cloud-based BIM platform. • eXtended reality (XR) is the final tool to reach new levels of communication and a wider audience characterised by experts in the construction sector and virtual and non-expert tourists.