Markos Katsianis, University of Patras, Kostas Kotsakis, Aristotle University and Filippos Stefanou, Paliambela Kolindros Archaeological Programme

Keywords: 3D models, GIS, archaeological excavation, Neolithic, Paliambela Kolindros

Introduction

Between 2000-2009 the Paliambela Kolindros archaeological project advanced one of the first working examples regarding a full 3D workflow in excavation recording and interpretative reasoning (Katsianis et al. 2008). In the meantime, improved recording equipment, advanced software solutions and novel intra-site applications both in the commercial and open-source domain have opened up new opportunities for the widespread integration of 3D spatial technologies within archaeological fieldwork.

The aiming and anticipation of these breakthroughs has been a key incentive in this initial attempt to integrate 3D and GIS technology to mediate the entire interpretative circle towards multi-faceted data rich interpretations. This digital approach apart from the ongoing work in Paliambela Kolindros has selectively been used as a means to enhance paper-based archives in Greece, such as Toumba Thessaloniki and the Cave of Agia Triada, Karystos (Katsianis et al 2015).

In light of recent developments and with a view to re-activate both the approach and the actual information collected so far, this presentation attempts to review the entire methodology and assess digital knowledge production issues with respect to 3D data enhancement, archiving and re-use.

Methods

The 3D workflow in Paliambela Kolindros aimed to integrate GIS as an interpretive tool that would assist in the spatial representation, stratigraphic reasoning, object correlation and phasing. It aimed to record the excavation procedure and allow the flexibility for an ever-changing engagement with the excavation archive at a post-excavation level. Excavation in this sense, was seen not as a destruction, but as a computer-assisted ‘metaphor’ from archaeological matter and excavation action into the body and flavor of a digital surrogate.

The means were the integration of recording methodologies that wouldn’t break the chain of their analogue predecessors, as well as their complementary function. Excavation forms were transcribed in digital format, while spatial measurements and image/drawing documentation was combined into 3D geometries to be viewed within a 3D GIS viewing environment. By carefully breaking up the world of excavation into meaningful entities using semantic modeling standards, i.e. CIDOC-CRM, a mechanism that would allow the exploration of excavation objects, features and observations in 3D, their collation with specialist feedback and their spatial statistics was established in order to facilitate the excavation archive to be gradually re-connected into a coherent whole, the same time allowing additional or competing interpretations to enter the archive (Katsianis 2012). The addition of a custom archaeological orientated interface to foster improved interaction with the excavation space was a further means to invite the excavators and specialists to use the system in all aspect of the excavation process (Tsipidis et al 2011).

Findings and argument

In the past few years technological change is so rapid that multi-year archaeological projects usually end up with a very diverse array of documentation media including  various levels of detail. In Paliambela Kolindros, ten years after the original research input:

1. The system has been mainly used for data entry and rarely for data exploration and interpretation – the custom interface was the first to become outdated.
2. Digital data feed was never completed in full; as a result the record remains partially analog/digital impeding a coherent engagement with it, even after all this time.
3. The excavation ontology still has loose ends both in our example, but apparently also in actual conceptual reference model definitions (i.e. the need for CIDOC-CRM extensions)(Χρηστάκη et al 2017).
4. Keeping up with technological change has been a major problem in terms of both institutional (maintenance of infrastructure and digital competence) and operational (integration of new procedures) capacities.
5. New recording methods (3D photogrammetry) resulting in more accurate spatial models have been introduced, however their results have not been integrated with the rest of the data infrastructure.
6. The infrastructure still works and can receive new forms of data, so the potential is still there.

In this sense, new research directions are to be explored. Although knowledge production at the trowel’s edge using digital media has received ample attention, e.g. Taylor et al. 2018, Dell’ Unto et al 2017), a special focus should be directed towards the interpretation of mixed (analog/digital) excavation archives. Is it possible to consider the excavation process as a historically specific ‘metaphor’ into an archive to be further transformed and re-interpreted? Is it possible to understand the archive as a process?

In the framework of Ariadne+ project a pilot portion of the digital excavation record compiled will be archived and disseminated. To achieve this, it is necessary  to re-engage with the excavation as an archive in order to try answering key questions as well as experiment with new forms of complementary knowledge production strategies.

For example new spatial products that may overlap with previous representations can be integrated within the system. Experimenting with new forms of 3D recording allows to both record the same features anew or use a retrospective photogrammetric approach (Wallace 2017) by re-processing old images (leftovers) from previous 2D documentation procedures using 3D photogrammetry into new and more elaborate 3D models. In both cases, the resulting models can be integrated into the same GIS environment. Do these different digital versions of the same ‘reality’ alter our original view on things?

Likewise, the digital creation process can be re-visited and re-processed to correct mistakes, identify graphical generalizations or simply fill in missing geometries that are affecting spatial comprehension.

Furthermore, the integration of finalized specialist studies results can be visualized and collated with original onsite interpretation to assess their level of agreement (e.g. density of animal bones or molluscs).

Finally, new geovisualisation methods can be explored in order to place the interpretive process not so much in a realistic embodied virtual environment (e.g. Forte 2014), as within an interactive learning 3D data visualisation platform (virtual vs map-like representation environments).

The combination of the above provides a step towards the engagement with an active (ongoing) archive that, a) is distanced from the moment of excavation and b) aims to collate the findings from interpreting the digital surrogate with the original onsite interpretation. Would onsite and ‘desk chair’ interpretations match? Is low quality or missing information depreciative of our visualizations and how much does this matter?

Conclusions

An excavation record can never be complete in either the philosophical, practical and/or digital sense. Also, we have never been media-less. Interpretation in archaeological knowledge production processes may be more affected by media diversification than technological change per se. In addition, archaeology will always have to look back to already compiled knowledge, re-process, re-evaluate and re-combine with new data that are each time more distanced from reality and increasingly black-boxed. The revisitation of mixed media excavation archives or – to put it differently – open ended archives, provides the opportunity to view archaeological knowledge building as a constant process, which necessarily includes the iterative evaluation of trans-mediation practices.

 

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