Fixed‐frequency Radio‐wave Imaging of Subsurface Archaeological Features: A Minimally Invasive Technique for Studying Archaeological Sites*

Abstract

In memoriam Tony Clark Sadly, this research marked the last field visit to the test site that the authors were able to share with their colleague Tony Clark. His enthusiasm, experience and encouragement inspired us to complete this project that, to many, must have appeared as grown men at play in a sand pit.A new approach to subsurface exploration has been developed, based on fixed-frequency radio-wave illumination from a buried transmitter. Data are collected from a buried, continuous wave source with a phase-coherent surface-scanning receiver and recorded in a digital archive from which images of the archaeological features are subsequently produced. An important feature of this approach is the opportunity to separate the data collection and archive functions, which form an uncompromised record of the site, from the more subjective image formation function. This paper reports the results of a feasibility assessment programme and discusses the future application of the method to real archaeological sites.

Detecting Trends in the Prediction of the Buried Past: A Review of Geophysical Techniques in Archaeology*

“…Although the majority of the GPR surveys that are undertaken are to investigate targets buried in the soil, high‐frequency antennas are often used for investigating cavities in walls. As an alternative, Somers et al . (2005) reported in Archaeometry a trial of a continuous fixed radio frequency system, where the transmitter is separated (down a borehole or on the far side of a wall) from a passive recorder that moves over a grid at the surface.…”

The application of geophysical methods to archaeological prospection

“…The resolution of a synthesized system will be determined by the frequency increment and number of steps used. Somers et al (2005) demonstrate an alternative approach to subsurface imaging by introducing a radio frequency source beneath the intended target through a small diameter borehole. The energy from the buried source then passes back up to the ground surface having been modified, in terms of both amplitude and phase, by the illuminated archaeological features.…”

Analysis of Standing Waves on GPR Hyperbolic Travel-Time Responses - Case Studies in a Fractured Granitic Rock and a Deteriorating Coastal Structure

“…Radar standing waves can be generated from an EM-wave source (Jackson 1998). EM standing waves may also occur when using GPR to detect caves (Somer et al 2005). Migration is often used to move dipping reflectors to their true subsurface and collapse the hyperbola in GPR data processing (Daniels 2004).…”