Development of a methodology for non-destructive studies of wall paintings in situ: The palimpsest of the Magdalen Chapel of St. Emmeram, Regensburg

该项目的总体目标是制定一个无损的协议，在现场检查壁画。将研究里根斯堡圣埃默拉姆的抹大拉教堂的独特的palimpalm，以优化方法。勃兰登堡大教堂回廊的壁画已经被广泛研究，将作为验证案例进行进一步研究。对所用材料的识别和对其物理化学性质的评估可以将各个层分配到特定的绘画阶段，以确定后续干预措施，以及选择适当的保护-修复策略。壁画的材料表征，由于其不可估量的价值，复杂的地层以及非均质的物质性，是具有挑战性的。从分析的角度来看，这意味着在尊重艺术品完整性的同时，尽可能多地获取有关有机和无机化合物的信息。这种要求的解决办法是使用非破坏性、互补性和便携式分析和数字化工具。该工作计划包括由保护人员结合档案研究和数字文档（摄影测量，紫外荧光摄影，meetings ®MAP）进行检查。一个双传感器超光谱成像系统（范围400-2500纳米），一个宏观X射线荧光扫描仪和一个三维数字显微镜将辅以精确的分析工具，如便携式拉曼和中红外光谱仪，用于材料表征。红外热成像和太赫兹光谱将分别用于解决保护问题和调查隐藏的油漆层。能够记录空间分辨光谱的成像系统将用于创建跨表面的不同元素/化合物的映射。将原本无法识别的图案可视化，对于回答保护和艺术技术问题将是极其重要的。尽管这些方法在文化遗产研究中具有巨大的潜力，但由于成本高、实施耗时以及生成数据的复杂性，这些方法尚未在该领域得到常规应用。该项目的主要任务是优化现场测量活动的分析方法，创建历史材料的多模式光谱数据库，以及实施用户友好的数据处理协议。我们的研究将在保护-恢复实践中引入最先进的技术。该项目基于保护-恢复和材料科学之间强有力的跨学科互动。这些发现将为进一步的研究奠定基础，例如在艺术史领域。抹大拉小教堂的壁画将是清晰的，也为公众访问。这将提高小教堂在教科文组织世界遗产里根斯堡中的知名度。

The overall aim of the project is the development of a non-destructive protocol for the examination of wall paintings in situ. The unique palimpsest of the Magdalen chapel of St. Emmeram, Regensburg, will be studied to optimize the methodology. The wall paintings in the Brandenburg cathedral cloister, already extensively studied, will be further investigated as a validation case.The identification of the used materials and the assessment of their physico-chemical properties allow to assign individual layers to a specific painting phase, to identify later interventions, as well as to choose proper conservation-restoration strategies.The material characterization of wall paintings, due to their inestimable value, complex stratigraphy as well as heterogeneous materiality, is challenging. From an analytical point of view, this means to acquire as much information as possible about organic and inorganic compounds while respecting the integrity of the artwork. The solution to such requirements is the use of non-destructive, complementary and portable analytical and digital tools. The work plan includes the examination by conservators combined with archival research and digital documentation (photogrammetry, UV fluorescence photography, metigo®MAP). A double-sensor hyperspectral imaging system (range 400-2500 nm), a macro X-ray fluorescence scanner and a 3D digital microscope will be complemented by punctual analytical tools such as portable Raman and mid-infrared spectrometers for material characterization purposes. Infrared thermography and Terahertz spectroscopy will be applied to address conservation issues and to investigate hidden paint layers, respectively. The imaging systems that are able to register spatially resolved spectra will be used to create mappings of different elements/compounds across the surface. The visualization of patterns that otherwise are not recognisable will be extremely important to answer conservation and art-technological queries. Despite their great potential for cultural heritage studies, these methods are not yet routinely applied in the field due to high costs, time-consuming implementation and the complexity of the generated data.Milestones of the project will be the optimization of the analytical methods for in situ measurement campaigns, the creation of multimodal spectral databases for historical materials and the implementation of a user-friendly data treatment protocol. Our research will introduce state-of-the-art techniques in the conservation-restoration practice. The project is based on a strong interdisciplinary interaction among conservation-restoration and material sciences. The findings will assure the basis for further research, e.g. in the field of art history. The wall paintings of the Magdalen chapel will be legible and accessible also for the general public. The visibility of the chapel in the context of the UNESCO World Heritage Site of Regensburg will thus be enhanced.