Berdien De Roo

Bridging Archaeology and GIS: Influencing Factors for a 4D Archaeological GIS

In archaeology, the intensive application of Geographical Information Systems (GIS) with their specialized capabilities in analysing spatial objects and relations, is hampered by the data particularities. Consequently, the idea arises to develop a comprehensive four-dimensional (4D, i.e. 3D and time) GIS tailored to archaeology, which would facilitate simultaneously handling the spatial and temporal dimensions. This paper endeavours to propose a methodological framework for the development of such a 4D archaeological GIS. This methodology is centred on the usability of the system and therefore integrates a methodology based on human cognition and the approach of the user-centred design cycle. The proposed framework consists of three pillars: (i) the user-oriented, (ii) data-oriented and (iii) analysis-oriented pillar.

A survey on the use of GIS and Data Standards in Archaeology

Geographical Information Systems (GIS) have been used in various archaeological projects. However, the archaeological data particularities (three-dimensionality, temporal dimension, imperfection) hamper the exhaustive application. A 3D or 4D (3D + time) GIS that is specifically tailored to archaeology may accordingly be beneficial. To develop such a system, a human-centred design, which considers the needs and viewpoints of the users in a four stage, iterative design cycle can be used. This paper focusses on the first two stages, the context of use description and the specification of the user requirements, by means of a user survey and so, does not address the proper design. The survey results clarify the widespread use of GIS in archaeology and the relatively high rate of expertise. Users require storing both raw and interpreted data, handling multiple temporal categories and imperfection. Furthermore, the use of data standards and metadata is limited and has to be encouraged.

Information flows as bases for archeology-specific geodata infrastructures: An exploratory study in flanders

Accurate and detailed data recording is indispensable for documenting archeological projects and for subsequent information exchange. To prevent comprehension and accessibility issues in these cases, data infrastructures can be useful. The establishment of such data infrastructures requires a clear understanding of the business processes and information flows within the archeological domain. This study attempts to provide insights into how information is managed in Flemish archeological processes and how this management process can be enhanced: an exploratory study based on an analysis of the new Flemish Immovable Heritage Decree, informal interviews with Flemish archeological organizations, and the results of an international survey. Three main processes, in which certified archeologists and the Flemish Heritage agency are key actors, were identified. Multiple types of information, the majority of which contain a geographical component, are recorded, acquired, used, and exchanged. Geographical information systems (GIS) and geodatabases therefore appear to be valuable components of an archeology‐specific data infrastructure. This is of interest because GIS are widely adopted in archeology and multiple Flemish archeological organizations are in favor of a government‐provided exchange standard or database templates for data recording. Furthermore, free and open source software is preferred to ensure cost efficiency and customizability.

Accurate and Cost-Efficient 3D Modelling Using Motorized Hexacopter, Helium Balloons and Photo Modelling: A Case Study

The destructive nature of archaeological excavations and the spatial character of archaeological finds make 3D models valuable contributions to the documentation of archaeological information. Laser scanning allows highly accurate 3D reconstructions, but involves considerable costs and expert knowledge. Therefore, photo modelling could be considered as a useful alternative. In this paper, we will demonstrate on the one hand the cost-efficiency and the consequent time-efficiency of the technique and on the other hand its (sub-decimeter) accuracy. Furthermore, the possibilities and advantages of motorized unmanned aerial vehicles (UAV) and helium balloons as airborne platform for image acquisition are shown. For this purpose, a case study is performed at the Mayan archaeological site of Edzna (Mexico). Using the Structure from Motion (SfM) and Multi-View Stereo (MVS) algorithm, terrestrial and aerial photographic recordings are processed into the final 3D models. For the quality assessment the photographic recordings are supplemented with topographic measurements.

The temporal dimension in a 4D archaeological data model: applicability of the geoinformation standard

Moving beyond the traditional border of two-dimensionality towards handling the third and even fourth, temporal, dimension in a GIS has been attracting many researchers. Archaeological data are inherently 3D and linked with time, which makes a 4D GIS tailored to archaeological data beneficial. Such a system would facilitate the handling of the three spatial and temporal dimension simultaneously and so enable better insights and more complex analyses. Its basis must be a conceptual data model, which pays attention to existing data models and standards. Therefore, this chapter focusses on the applicability of the ISO 19108 geo-information standard to describe temporal information, which is a crucial aspect in archaeological research. For a set of six common temporal categories, e.g. the excavation time, the appropriate description according to this standard is determined. This will indicate in which cases the internationally recognized standard is suitable for use in an archaeological data model. Furthermore, part of the West European archaeological time scale is constructed as temporal ordinal reference system. For the first version, the NBN EN ISO 19108:2005 structure is used, whereas the second and third are based on geological variants. The results of the performed analysis are favorable to the usability of the ISO 19108 standard in archaeology; however, other temporal standards or data models may yield up better results.

Usability Assessment of a Virtual Globe-Based 4D Archaeological GIS

Acquired using 3D technologies, archaeological data is increasingly represented via 3D visualizations. For analysing, interpreting and exchanging, these data are unfortunately mostly reduced to two dimensions. Therefore, a 4D archaeological GIS that integrates 3D representations and analytical functionalities will contribute to different parts of the archaeological workflow from fieldwork preparation over analysis to reporting. Such a 4D approach will facilitate better and more integrated insights and allow more complex analyses and interpretations. Incorporating such a 4D archaeological GIS in a web-based environment will even increase the benefits as this could function as a virtual workspace. Since virtual globes have proven their capabilities to manage and visualize 3D data in non-expert applications, a prototypical 4D archaeological GIS was developed based on the virtual globe Cesium. This paper demonstrates by means of a usability test with employees of a Flemish archaeological organization that the concept of such a low-threshold application is supported by the intended end-users. Although some usability problems were encountered and the functionalities of the prototype are rather limited, extending and further developing the system could result in a valuable research tool for archaeology.

From Virtual Globes to ArcheoGIS: Determining the Technical and Practical Feasibilities

Abstract Web mapping and virtual globes are increasingly used to communicate 3D geospatial results to fellow researchers and the public. The lack of analytical functionality nonetheless restricts their utility in research, including archaeology. Integrating both 3D and analytical functionalities should result in a 4D archaeological GIS that can be used throughout the archaeological workflow. This paper investigates the feasibility of extending a virtual globe to such a user-friendly system. This involves a technical assessment by comparing the characteristics of virtual globes with user, data, functional, and organizational requirements. The prototypical implementation consequently uses Cesium® as basis. This prototype served for the practical feasibility evaluation. The usability test with two Flemish archaeological organizations has shown broad support for a low-threshold 4D ArcheoGIS from its potential end-users. Although public activities, analyses, and fieldwork preparations were mentioned as application domains, extending the system to fit archaeological workflows or a cyberinfrastructure is necessary.

Determining geometric primitives for a 3D GIS easy as 1D, 2D, 3D?

Acquisition techniques such as photo modelling, using SfM-MVS algorithms, are being applied increasingly in several fields of research and render highly realistic and accurate 3D models. Nowadays, these 3D models are mainly deployed for documentation purposes. As these data generally encompass spatial data, the development of a 3D GIS would allow researchers to use these 3D models to their full extent. Such a GIS would allow a more elaborate analysis of these 3D models and thus support the comprehension of the objects that the features in the model represent. One of the first issues that has to be tackled in order to make the resulting 3D models compatible for implementation in a 3D GIS is the choice of a certain geometric primitive to spatially represent the input data. The chosen geometric primitive will not only influence the visualisation of the data, but also the way in which the data can be stored, exchanged, manipulated, queried and understood. Geometric primitives can be one-, two- and three-dimensional. By adding an extra dimension, the complexity of the data increases, but the user is allowed to understand the original situation more intuitively. This research paper tries to give an initial analysis of 1D, 2D and 3D primitives in the framework of the integration of SfM-MVS based 3D models in a 3D GIS.