Ground Penetrating Radar

There are many ancient masonry arch bridges still in use within the actual transportation. Some of these bridges are in need of special attention because they are subject to potentially destructive conditions, such as increased traffic loads and intense vibrations produced by their new functions, and these stresses are compounded by their age. To preserve these functional structures, structural assessment is necessary or, at least, highly recommended. However, many of the details of these structures are underground and are therefore hidden from view. In recent decades, ground-penetrating radar (GPR) has shown potential for internal bridge evaluation. The Roman Bibei bridge (Spain) was surveyed with GPR to analyse its inner state of conservation. The GPR survey was conducted using 250 and 500 MHz antennas. The interpretation and analysis of the GPR data were supported by finite-difference time domain numerical modelling based on the precise external geometry provided by three-dimensional laser scanning methods. Both real and synthetic results reveal that GPR evaluation provides unknown structural details and possible modifications over time. The internal ring stone thickness was also measured, which represents valuable information for engineers to perform an exhaustive assessment of the load carrying capacity of the bridge.► This work presents the GPR assessment of an ancient masonry arch bridge. ► The study includes the use of metrical documentation obtained by laser scanner. ► The real GPR results were also compared to FDTD modelling data. ► The FDTD was built considering the external geometry provided laser scanning. ► The results revealed structural details and possible modifications over time.

Field experience has shown that soil conditions can have large effects on Ground Penetrating Radar (GPR) detection of landmines. We discuss available models for the prediction of the dielectric constant from soil physical properties including bulk density, soil texture, and water content. The soil dielectric constant determines the attenuation of the radar signal. The contrast between the dielectric constant of

A landscape-scale conception of the circa 1688–1715 CE Seneca occupation at the White Springs Site (NYSM 1952; RMSC Plp-018), located in Geneva, NY, is important for understanding their built environment during a period of residential upheaval. This paper reports on approximately five hectares of high-resolution, multi-instrument archaeogeophysical surveys. These surveys allowed engagement with layered, temporal contexts and the gathering of otherwise inaccessible information. In combination with excavation, surface survey, and historic research, archaeogeophysical techniques provided expanded access to the site, a settlement size estimate of 1.42–2.75 ha, and tentative evidence for a palisade at the White Springs Site. The interplay between archaeogeophysics and other techniques was critical to this undertaking.