Use of ground‐probing radar and resistivity surveys for archaeological investigations

Abstract

In Japan, geophysical methods are normally used to estimate the distribution of cultural relics before digging. Objects of archaeological interest are usually located within a few meters of the surface. Therefore, geophysical methods suitable for archaeological exploration are those which provide high resolution at shallow depths. The most commonly used geophysical methods are ground‐probing radar, resistivity, and magnetometry. Of these methods, we used mainly ground‐probing radar and resistivity surveys in archaeological investigations at four sites. Three of the sites were in Gumma Prefecture (Japan); they were covered with volcanic deposits (loam or pumice). Using ground‐probing radar, we were able to locate ancient dwellings, burial mounds, and a distribution of archaeologically significant “culture layers.” At the other site, in Nara Prefecture, we located part of the remains of an ancient city. In this investigation, the resistivity method and ground‐probing radar were combined to determine the location of an underground water course within the ancient city.

Selected radar images of man‐made underground galleries

“…In the 1980s, GPR started to be used for shallow investigations, where attenuation phenomena are less, using 500 MHz to 1 GHz antennae, which give an appropriate resolution (Ulriksen, 1982;Glover, 1987). During this period it is possible to find the first applications of GPR in archaeology (Hara and Sakayama, 1984;Imai et al, 1987). In the 1990s, new antennae with lower (10, 20 and 50 MHz) and higher (2.5-3 GHz) centre frequency were used for the GPR and this allows its use in many new applications: glaciology, pavement inspection, mine detection, construction, etc.…”

Remote Sensing of a Roman Pottery Workshop. Report on a Geophysical Survey Carried out in Crikvenica (Ancient Ad Turres, Croatia)

“…GPR is a very mobile and effective method of subsurface geophysical prospection, especially for archaeology (see among others, Imai et al, 1987;Conyers, 2013Conyers, , 2016aMieszkowski et al, 2014;Welc et al, 2014aWelc et al, , b, 2015. The GPR device, composed of a transmitting-receiver antenna and a steering device, emits electromagnetic waves to a ground with high and ultra-high frequency radio waves (10 MHz -2 GHz) and registers impulses reflected from lithological boundaries and buried objects.…”

Mapping anthropogenic fill with GPR for unmarked grave detection: a case study from a possible location of Mokare’s grave, Albany, Western Australia

“…GPR has been used for geological applications since the 1960s, and since the mid1980s has been increasingly adopted within the engineering and archaeological communities (e.g. Bevan, 1991;Cook, 1960;Imai et al, 1987;Gracia et al, 2000;Reynolds, 1997;Watters and Hunter, 2004).…”