A Comparison of Volumetric Reconstruction Methods of Archaeological Deposits Using Point-Cloud Data from Ahuahu, Aotearoa New Zealand

Matthew Barrett,Stacey Middleton,Joshua Emmitt,Thegn N Ladefoged,Timothy Mackrell,Patricia Pillay,Bruce Floyd

doi:10.3390/rs13194015

Matthew Barrett, Stacey Middleton + Show 5 more

Open Access

https://doi.org/10.3390/rs13194015

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Journal: Remote Sensing	Publication Date: Oct 7, 2021
Citations: 5	License type: CC BY 4.0

Affiliation: University of Auckland

Abstract

Collection of 3D data in archaeology is a long-standing practice. Traditionally, the focus of these data has been visualization as opposed to analysis. Three-dimensional data are often recorded during archaeological excavations, with the provenience of deposits, features, and artefacts documented by a variety of methods. Simple analysis of 3D data includes calculating the volumes of bound entities, such as deposits and features, and determining the spatial relationships of artifacts within these. The construction of these volumes presents challenges that originate in computer-aided design (CAD) but have implications for how data are used in archaeological analysis. We evaluate 3D construction processes using data from Waitetoke, Ahuahu Great Mercury Island, Aotearoa, New Zealand. Point clouds created with data collected by total station, photogrammetry, and terrestrial LiDAR using simultaneous localization and mapping (SLAM) are compared, as well as different methods for generating surface area and volumes with triangulated meshes and convex hulls. The differences between methods are evaluated and assessed in relation to analyzing artifact densities within deposits. While each method of 3D data acquisition and modeling has advantages in terms of accuracy and precision, other factors such as data collection and processing times must be considered when deciding on the most suitable.

Highlights

Three-dimensional recording in archaeology is an increasingly applied and accessible methodology
We compare surface areas and volumes created with data collected by three different methods commonly employed in archaeological inquiry: total station (TS), light detection and ranging (LiDAR) using simultaneous localization and mapping (SLAM), and photogrammetry (PG)
The comparative analysis suggests that the SLAM technology is not well suited towards irregular, relatively small shapes, within a natural environment such as the sand dune swale at Waitetoke without regular surfaces such as those found on buildings and some rock formations

Summary

Introduction

Three-dimensional recording in archaeology is an increasingly applied and accessible methodology. The reduction in costs of specialized equipment and computing power, in addition to simplified workflows, has meant that such recording methods can be applied in a wide range of contexts (e.g., [1,2,3,4,5]). Different methods can be used to record and create volumes to various levels of detail. These differences require quantification to determine what influence, if any, they have on the creation of volumes. We compare surface areas and volumes created with data collected by three different methods commonly employed in archaeological inquiry: total station (TS), light detection and ranging (LiDAR) using simultaneous localization and mapping (SLAM), and photogrammetry (PG). We compare two modeling methods that are readily available in a range of software, triangulated meshes and convex hulls, to test what effect these have on the resulting

Results

Discussion

Conclusion