L. Valdeon et al., A METHOD TO ASSESS SPATIAL COORDINATES IN ART AND ARCHAEOLOGICAL OBJECTS - APPLICATION OF TOMOGRAPHY TO A DOLMEN, Journal of archaeological science, 24(4), 1997, pp. 337-346
A method to determine the values of spatial coordinates of bodies, spe
cifically adapted to study art and archaeological objects, was develop
ed and tested on a dolmen made of granite in north-west Spain. This me
thod, based on geometric principles, comprises an easy-to-assemble rig
id structure as a physical support, and software based on the algorith
ms discussed below, which together provide a rapid and inexpensive mea
ns of assessing coordinates. One of the main features of this procedur
e is the ability to quantify the accuracy of the coordinates being cal
culated according to the quality of the input measurements. The simpli
city of obtaining data means that the method can even be performed upo
n rough and irregular-shaped objects, and in zones where other instrum
ents are difficult to handle; for example, the interior of dolmens or
small cavities. A demonstration of the method was performed upon an up
right stone of a megalith in north-west Spain (Axeitos Dolmen, La Coru
na). The coordinates of many points of measurement surrounding the obj
ect, combined with parameters from ultrasonic signals, were used to ac
hieve three-dimensional tomography. Considering the experimental error
s produced by different operators, the accuracy achieved when estimati
ng the coordinates was better than 1 cm. The tomograms obtained have b
een employed to assist in the evaluation of damage to this megalith. (
C) 1997 Academic Press Limited.