Graphical Data Flow Based in TLS and Photogrammetry for Consolidation Studies of Historical Sites. The Case Study of Juromenha Fortress in Portugal

Abstract. This paper discusses the graphical data flow, based on terrestrial laser scanning (TLS) and photogrammetry, for the conservation and rehabilitation project of the Fortress of Juromenha, located nearby the Portuguese-Spanish border in the Alentejo Province. First, we describe the strategy of data acquisition including GPS positioning, drone imagery, ground based imagery, and TLS survey. For the data input, this study considers two types of natures: quantitative and qualitative. Quantitative means anything that can be quantified such as a measurement, an orthoimage, a point cloud or a 3D model. Qualitative means more intangible information such as a perspective on the state of conservation of a surface, a texture, or an ambience. Second, we illustrate the processing step highlighting the challenges and defining the outcomes. Next, it is detailed what kind of data was extracted to prepare the basis for the documents to be used on the conservation project. This section is complemented with the analysis on how data was shared among the project team and how it was used. Finally, it is discussed how the nature of the data and information generated influenced the consolidation design.