Mona Hess

The “Stone Witnesses Digital” project ensures the exemplary documentation of a selected number of German Jewish graveyards. This paper presents the results from the first years of the project’s geomatics work, including the development of an integrated multi-sensor workflow for 3D imaging—ranging from geographic-scale documentation of entire graveyards (1:200 scale) to detailed feature imaging of individual gravestones (1:20 scale). The workflow supports the long-term research project on Jewish sepulchral culture and brings together expertise from Jewish Studies, Digital Technologies in Heritage Conservation, and Historic Building Research. The overarching scope is to document the location and context of gravestones, their materiality, decorative elements, inscriptions, and the meanings embedded within them—summarized under the guiding concept “Space, Form, Inscription.” The aim of the project is to create a comprehensive digital dataset that documents inscriptions as well as the spatial and structural characteristics of gravestones, thereby ensuring their long-term preservation and making them accessible for further academic research. To achieve this, the workflow must integrate various sensing and 3D imaging techniques, ensure reliable and sustainable data storage, and support reproducible dataset creation for spatio-temporal analyses and long-term monitoring of graveyards throughout the 24-year project period. It also enables the combination of advanced sensing technologies with semantic web standards and facilitates the creation of informative Open Access outputs compliant with FAIR data principles.

The digital documentation of heritage architecture, particularly historic wooden roof structures, has gained significant importance in recent years. Heritage Building Information Modelling (HBIM) has emerged as a crucial field that focuses on the digital representation and management of historic buildings. However, modelling heritage structures in accordance with BIM standards poses challenges due to the complex geometries and specialized information inherent with heritage timber structure. This article presents a workflow that illustrates the integration of an automated, AI-supported analysis of wood knottiness to assess unknown strength values of aged heritage timbers within building life cycle management and supporting the BIM framework. For this purpose, an algorithm for automatic wood knottiness estimation has been developed and implemented as a smartphone-based app-prototype, which facilitates efficient data collection, automatic analysis, and seamless integration into the BIM modelling process, while minimizing potential data loss during exchange.

The concept of Digital Twin has attracted growing interest within research communities in recent years, including heritage conservation. It combines detailed geometric documentation, real-time monitoring, and semantic information to create dynamic digital replicas of historic buildings. This paper presents the results of a scoping review of 204 peer-reviewed studies published between 2020 and 2025. The aim is to identify the main technologies, devices, and methods used to develop a Digital Twin for heritage buildings. The review reveals that terrestrial laser scanning, UAV photogrammetry, BIM, and IoT sensor networks form the core technological base. It also highlights the growing use of artificial intelligence for automated defect detection, predictive maintenance, and semantic processing. Based on the reviewed literature, the paper introduces a six-stage workflow for building a heritage Digital Twin, covering baseline documentation, static reality capture, semantic modelling, sensor integration, data fusion, and operational use. The findings show a clear shift from static 3D documentation toward dynamic, data-rich systems that support continuous monitoring and more informed decision-making. However, the review also identifies major challenges, including limited interoperability, complex data integration, incomplete AI validation, and long-term digital preservation issues. Overall, the study outlines the current state of Digital Twin technologies in architectural heritage and identifies key areas that require further research to support reliable and sustainable applications.

This paper presents a mask-aware multi-stage depth enhancement framework for digital documentation of historical timber surfaces using RGB–Stereo-IR fusion. Accurate geometric recording of aged wood features such as wooden knots remains challenging due to uneven illumination and weak texture. The proposed pipeline, which aims to stabilise depth geometry under uneven illumination and low-texture surface conditions, integrates object detection, instance segmentation and confidence-guided depth refinement across three stages: (A) TV(total variation)-regularized mask-aware refinement, (B) confidence-weighted multi-view fusion, and (C) patch-based stereo reconstruction. Experiments on historical timber beams under varying illumination demonstrate improved depth completeness and geometric consistency, achieving a residual standard deviation below 0.6 mm in bright scenes and stable reconstruction in low-light conditions. The framework offers a practical solution for depth reconstruction of cultural heritage timber, supporting more reliable feature detection and analysis.

In this paper we introduce and report on the project “Steinerne Zeugen digital – German-Jewish Sepulchral Culture between the Middle Ages and Modernity. Space, Form, Inscription.” A project report on the first years of the project will be given, with a focus on the design and implementation of interdisciplinary, digitally integrated workflows. We will present and compare different technical and methodological approaches applied to three cemeteries and analyse the challenges encountered at the interface of interdisciplinary collaboration, particularly regarding data interoperability, semantic consistency, scalable data processing, and long-term preservation of complex 3D datasets. An outlook on future developments and specific research questions in geomatic engineering will be given, addressing automated feature extraction, advanced spatio-semantic querying, and FAIR-compliant data infrastructures for sustainable digital heritage documentation and analysis within this long-term project.

The safeguarding and preservation of architectural heritage are pivotal to maintaining Europe’s cultural identity, while current documentation practices remain fragmented and unevenly applied across regions. This article critically evaluates existing standards, recommendations, and best practices to identify gaps and inconsistencies in architectural documentation methodologies across European Countries. Based on this evaluation, we propose an integrated and adaptive European recommendation for architectural heritage documentation.

Steinerne Zeugen digital: Ein Forschungsprojekt zur Erschließung jüdischer Friedhöfe was published in Spuren jüdischen Lebens in Bayern on page 157.

Stability of historic wooden constructions is changing with time and should be inspected appropriately for risk assessment and prevention. The stability or strength values of built-in historic timber are difficult or even impossible to be derived without invasive investigation, but this is particularly problematic for the monitoring of heritage objects. Luckily there are some visible timber surface features, like knots and cracks, which can act as individual evidence to estimate the wood strength as well as to adjust its grade class indicator. In the final project, we aim to compare different approaches for 3D digital documentation of historic wood timbers and focus on automatic knot detection using AI techniques. A first feasibility study reported here provides a scientific baseline for the development of an automated method to analyse historic timber stability using 3D surveying and recognised surface features. First results about texture and resolution properties are discussed here.

This article presents the current guidelines/standards for architectural documentation in various countries. Available regulations, applicable documents, technical guidelines, and good practices were analysed, together with selected examples of 3D digitisation projects. The results of the evaluation were compared with the guidelines for generating 3D documentation proposed by The Expert Group on Digital Cultural Heritage (EU) and Europeana. The analyses show no unambiguous hard technical guidelines. Still, there is a set of proposed guidelines and good practices to correctly carry out the 3D digitalisation process and the selection of equipment for the inventory of selected classes of object types. For this reason, it is recommended to detail the guidelines for the selection of equipment and the possible accuracy of the final architectural documentation derived from geospatial data.