A computerized system to determine the provenance of finds in archaeological sites using acoustic signals

Abstract

Some archaeological excavations require the accurate determination of the provenance of finds (three-dimensional location and orientation) for a subsequent spatial analysis. The traditional manual measurement using a grid reference is not a very efficient registration method. Some proposed computerized solutions based on total stations, photogrammetry and DGPS, are more effective but have some limitations. This paper presents a new acoustic localization system (3D-LOCUS) for measuring the three-dimensional position of finds in archaeological sites. The system can also be used for registering the size, shape and orientation of artifacts. 3D-LOCUS basically consists of a set of wireless rod-like pointing devices that are localized with a network of intelligent nodes installed above the excavation site. Archaeologists use the pointing device as a stylus to locate and outline the object under study. The main technological characteristics of the system are: omnidirectional wideband acoustic transducers, Bidirectional Time-Of-Arrival (BTOA) estimation, redundant ranging and robust trilateration. 3D-LOCUS achieves an accurate registration, even if used simultaneously to the digging labor, or in noisy or turbulent airflow conditions. We tested the system in the Gran Dolina archaeological site ( Atapuerca, Spain). The typical location accuracy is below 10 mm in natural conditions, and the achieved resolution is 5 mm, which allows us sketching objects with enough detail.