3D Spatial Analysis: the Road Ahead

In recent years, Geographical Information Systems (GIS) have become a widespread and increasingly used technology in various domains. GIS have proven their strength in archaeological research applications, such as the analysis of spatial relations between excavation objects and predictive modeling. Besides the increasing attention to GIS, in diverse research areas much interest has aroused to explore the potentials of three and even four dimensionality (3D/4D). In cultural heritage, this has mainly resulted in a proliferation of 3D digital visualizations, predominantly virtual reality models. Notwithstanding their impressive appearance and great value for publication purposes, the analysis and data exchange capabilities are generally abandoned. Integrating these two research trends will bring benefits to a wide range of domains. Although a 4D GIS would facilitate better insights and more complex analyses, in archaeology, realizing this combination is challenged by the diversity of archaeological data and its inherent complexity. Fully exhausting the power of GIS is currently improbable because archaeological data are more complex than most of the regular geospatial data. Therefore, a specifically to archaeology tailored 4D GIS based on a customized data model proves to be necessary. This paper first tries to present the state-of-the-art of current 4D data modeling in archaeology. Second, points of attention for future research directions are geared to this overview. Accordingly, integrating an object-oriented and event-driven approach is brought forward to take into consideration.

After 20 years of '2.5D' GIS work in Archaeology, we have seen in recent years the first signs that researchers are moving on to true 3D (volumetric) spatial representation and analysis - previously the preserve of oil geologists. At the same time, new technology is giving rise to a new boom in '3D' (actually still 2.5D) documentation and visualisation studies. This paper draws attention to the collection, management and analysis of true 3D spatial data from intra-site to landscape-scale contexts, drawing on data deriving from coring, geophysics, excavation, seismics, etc. The authors discuss current possibilities and desirable developments in 3D GIS.

Evangelidis, V., Tsiafaki, D., Mourthos, Y., & Karta, M. (eds). Mapping the Past, Plotting the Future: GIS in Archaeology, Maturity and Implementation. Proceedings of the workshop organised by the AeGIS Athena Lab, at the British School at Athens, Thursday 30 March 2023. Journal of Greek Archaeol..., 2024

2010

The paper presents an interdisciplinary project which is a work in progress towards a 3D Geographical Information System (GIS) dedicated to Cultural Heritage with a specific focus application on the Castle of Shawbak, also known as the "Crac de Montréal", one of the best preserved rural medieval settlements in the entire Middle East. We develop a set of tools for medieval archaeological analysis ranging from the production of traditional graphical documentation like orthophotos and low-resolution 3D models (VRML) to the use of 3D/2D GIS through the creation of centralized and exhaustive object storage tool both for archaeological and photogrammetric data. Using these tools archaeologists will be able to produce, store, visualize and manage both archaeological and 3D data, according to their needs. The Shawbak archaeological project is a specific and integrated project between medieval archaeological research, conservative restoration and site's valorization. Focusing mainly on stratigraphical analysis of upstanding structures provides archaeologists with a huge amount of data to collect on site and useful records that will be used to understand the structures from stratigraphical and technological point of views. The foundation stone for this project is the analysis of documents produced and used by archaeologists in order to identify specific archaeological requirements The first phase is to give archaeologists traditional photogrammetric tools so that they can be autonomous in producing graphical documents (taking photographs, photo orientation and traditional orthophoto generation). The second step is to develop a common model structure for both photogrammetric and archaeological data storage using a unique database and allowing to link archaeological data with 3D measurements. Specific photogrammetry tools dedicated to stone by stone measurement have been under development since 2000 to help archaeologists to easily produce photogrammetric surveys. These tools are now integrated in a more complex system which allows automatic production of 2D or 3D representations from archaeological database queries. The graphical 2D documents produced through this process look like the handmade drawings done by archaeologists using orthophotos. The 3D GIS is the last step of this chain and aims the automatic production of 3D models through archaeological database queries: these 3D models are in fact a graphical image of the database and at the same time the interface through which the user is able to modify it. This approach enables automatic 3D thematic representation and new archaeological analysis through bidirectional-links between 3D representation and archaeological data. All these developments are written in Java within Arpenteur framework.

2016

Several digital technologies are now available to record and document archaeological excavations. A large number of studies have been published concerning the use of laser scanning, image based 3D modelling and GIS. By integrating different typologies of 3D data from Uppåkra, an Iron Age central place in southern Sweden, this thesis focuses on the development and evaluation of how 3D Geographic Information Systems (3D GIS) affect archaeological practice. In specific a Digital Terrain Model (DTM) was created for the site and the surrounding landscape. A UAV (drone) was used to document the excavation area in higher resolution, and image based 3D modelling was used to record the ongoing excavation on a single-context level. These different typologies of data were subsequently imported in a 3D GIS system (ArcScene) in order to conduct various types of spatial analysis (e.g. hillshade and slope analysis) as well as to create 3D drawings of the excavated contexts, using the textured 3D models as a geometrical reference. The ability to virtually revisit previous stages of the excavation and the use of tablet PC’s for documentation and discussion at the trowel’s edge increased reflexivity on the excavation and stimulated on-site interpretation by the excavation team. The model based drawing approach furthermore improved the drawing resolution compared to traditional documentation using a total station, especially for complicated contexts. This approach allowed connecting different typologies of data in the same virtual space, 1) increasing the possibility of researchers and scholars to gain a complete overview of all the information available, as well as 2) exponentially increasing the possibilities to perform new analysis. The ability to interact and navigate with all the data in 3D improved the impact of the data and comes closer to simulating the real world. Though some challenges still have to be faced, such as inaccurate georeferencing and unrealistic colour projection, the method was found to significantly improve the documentation quality by creating a multi-scale 3D documentation platform. By further developing this method, it can help us to improve the standards of archaeological excavation documentation.

2014

Archaeology joins in the trend of three-dimensional (3D) data and geospatial information technology (geo-ICT). Currently, the spatial archaeological data acquired is 3D and mostly used to create realistic visualizations. Geographical information systems (GIS) are used for decades in archaeology. However, the integration of geo-ICT with 3D data still poses some problems. Therefore, this paper clarifies the current role of 3D, and the opportunities and challenges for 3D and geo-ICT in the domain of archaeology. The paper is concluded with a proposal to integrate both trends and tackle the outlined challenges. To provide a clear illustration of the current practices and the advantages and difficulties of 3D and geo-ICT in the specific case of archaeology, a limited case study is presented of two structures in the Altay Mountains.

The 3 Dimensions of Digitalised Archaeology. State-of-the-Art, Data Management and Current Challenges in Archaeological 3D-Documentation, Springer, Cham, 2024

Although the basics of 3D technologies developed rather early on, only today are we seeing a steep increase in the application of 3D technologies in archaeological practice. This volume aims to give a broad overview of possible applications in the field, but also to open a discussion about the challenges and problematic aspects of this method so far. Only if there is an awareness of the implications and challenges of implementing this new technology in the everyday practice of field and research archaeology can archaeology take full advantage of its possibilities. Keywords 3D technologies in archaeology • Digital archaeology • Digital archiving • Data management • Photogrammetry • 3D scanning in archaeology The application of new methods has had a lasting impact on our research questions, research setups and applied methodology-in short, they have deeply affected our understanding and practice of archaeology. Some of them have been labelled

During the last decade the contribution of GIS technology in recording and analysis of archaeological data has been significant. Although, however, the information that archaeologists record has a deeply 3D character, the analyses within GIS packages rely upon a 2D abstraction of reality. The approaches proposed so far for 3D archaeological GISs reveal some important drawbacks such as: bad quality of produced graphic objects representing spatial entities, complicated and timeconsuming techniques for the creation of 3D objects, inability of object manipulation in a true 3D GIS environment. In this paper, alternative methods of creating and analyzing 3D archaeological information are proposed; they are based on a commercial GIS package, with attempts to extend its options. The central aim is the realistic visualization of archaeological excavation data through 3D representations to help archaeologists have a reliable image of the excavation process and their interpretive results. In the first part, the spatial nature of archaeological research and the significance of the third dimension in excavation interpretation and analysis are introduced. In the second part, several techniques for 3D modeling and representation of the different data types are proposed, for: the excavation site and its greater landscape surroundings, geological layers captured during geological investigations, excavation units (the central spatial elements of the excavation process), finds (the material culture evidence within archaeological sites), plans and digital photographs of archaeological deposits (traced during excavation process). The procedure followed aims to facilitate a better data management of excavation context and provide useful insights during the interpretation process.

Papadopoulos, C., Paliou, E., Chrysanthi, A., Kotoula, E., and Sarris, A. 2015. Archaeological Research in the Digital Age. Proceedings of the 1st Conference on Computer Applications and Quantitative Methods in Archaeology Greek Chapter (CAA-GR). Pages 46-54, 2015

Recent advances in spatial technologies present new opportunities for augmenting existing excavation archives. This paper outlines methods and techniques for the transformation of spatial information recorded in these archives into 3D representations. Towards this end, the use of GIS can assist the modelling process, integrate spatial data produced using different modelling procedures and support the transcription of information held in diverse documentation means, both paper-based and digital. The outcome of such modelling exercises can enable new dynamic ways of interacting with an existing excavation archive within a 3D cartographic environment, thus allowing the improved understanding of stratigraphic relations and spatiotemporal patterning. Additional techniques for data grouping and quantitative analysis can facilitate further information extraction processes. Examples are used from recent work on the prehistoric sites of Thessaloniki Toumba and Ayia Triada Karystos.

The 3 Dimensions of Digitalised Archaeology, Springer, Cham, 2024

Between January and March 2020, the EAA Community for 3D-Technologies in Archaeology conducted an international online survey on the current use of image-based 3D technologies. The aim was to gain broader insight into the application of image-based 3D technologies in archaeological practice and cultural-heritage management. The survey made it possible to determine the most important aims of the use of 3D technologies, as well as providing an overview both of the software and data formats used and of current archiving practices for raw and/ or generated data. In this way, the main challenges for the further development of the techniques and the ongoing implementation of 3D technologies in practice can be identified.