Imaging of Scarce Archaeological Remains Using Microwave Tomographic Depictions of Ground Penetrating Radar Data

The Romano-British site of Barcombe in East Sussex, England, has suffered heavy postdepositional attrition through reuse of the building materials for the effects of ploughing. A detailed GPR survey of the site was carried out in 2001, with results, achieved by usual radar data processing, published in 2002. The current paper reexamines the GPR data using microwave tomography approach, based on a linear inverse scattering model, and a 3D visualization that permits to improve the definition of the villa plan and reexamine the possibility of detecting earlier prehistoric remains

A numerical investigation of the dispersion law of materials by means of multi-length TDR data

In this paper, we propose a method for retrieving the dispersion law of a material under test from multi-length TDR measurements in reflection mode, repeated at several frequencies. By replacing the multi-frequency measurements with measurements using multi-length TDR probe, it is possible to retrieve the complex equivalent permittivity of the material in a frequency band of interest. The proposed procedure does not require a priori knowledge of the type of dispersion law of the material, which instead can possibly be inferred from the measured data. The algorithm is validated using numerically simulated data obtained with the commercial code CST Microstudio®.peer-reviewe

Nuove tecniche di prospezione archeologica mediante strumenti multifrequenza

EnIn this work we present some results obtained in a measurement survey performed with a stepped frequency Ground Penetrating Radar (GPR). The GPR and the survey at hand have been conceived for archaeological purposes.The stepped frequency GPR has been developed by the Italian Research Consortium CO.RI.S.T.A. in the framework of the ARCHEO project, founded by Italian M.U.R.S.T. The system can work within a large bandwidth and both in ungated and gated mode. It is equipped with a positioning system able to move the transmitting and receiving antennas of the GPR independently on each other and to place them automatically and in a precise fashion. The GPR has been tested first in laboratory of CO.RI.S.T.A., then in a controlled site, and finally in the real archaeological site of Cales, near Capua (Southern Italy), preventively and appositely studied by a team of archaeologists. The final results obtained in the field have been coherent with a previous prospecting performed at Cales and have individuated some new further buried targets, whose nature is still unknown at the moment

Towards an operative use of remote sensing for exploring the past using satellite data: The case study of Hierapolis (Turkey)

This paper is focused on the presentation and discussion of an object oriented approach, applied to the Hierapolis (Turkey) site, to automatically detect the subtle features linked to buried archaeological remains. The data processing is applied twice: (i) first, globally at the whole image and, (ii) second, at the significant subsets identified by global analysis, in order to refine the previously obtained categorization. Object oriented approaches are usually based on two main steps: i) first the segmentation, ii) then the classification. Herein, we first performed the unsupervised classification step and, then, the segmentation. This choice is given by the specificity of archaeological issue, in particular: (i) the subtle features/targets to be identified are partially or totally unknown and characterized by a very small spectral separability from the background, and therefore (ii) the discrimination between archaeological class and substrates likely suffers significant confusion. To cope with these issues, the first step is based on an unsupervised classification, which provides a first ‘rough’ categorization of pixels; the second step, based on the segmentation, enables us to extract the geometric shape, and, in turn, to only categorize as archaeological class those pixels belonging to geometrically (rectangular and linear) shaped clusters. Outputs from this classification identify rectangular and linear features of archaeological interest whose size suggested that they may be a farm and some sectors of an aqueduct, respectively. Results from satellite based analysis were successfully evaluated by georadar and geomagnetic prospection along with field survey. From georadar and geomagnetic prospection we were able i) to confirm the presence of buried remains and ii) to detail and characterize these archaeological features at the subsoil level as well as to define the local stratigraphy. From field surveywe dated the detected buried remains to a period spanning from Imperial Roman to early Byzantine historical times

A method for extracting Debye parameters as a tool for monitoring watered and contaminated soils

Soil monitoring is a key topic from several perspectives, such as moisture level control for irrigation management and anti-contamination purposes. Monitoring the latter is becoming even more important due to increasing environmental pollution. As a direct consequence, there is a strong demand for innovative monitoring systems that are low cost, provide for quasi-real time and in situ monitoring, high sensitivity, and adequate accuracy. Starting from these considerations, this paper addresses the implementation of a microwave reflectometry based-system utilizing a customized bifilar probe and a miniaturized Vector Network Analyzer (m-VNA). The main objective is to relate frequency-domain (FD) measurements to the features of interest, such as the water content and/or the percentage of some polluting substances, through an innovative automatable procedure to retrieve the Debye dielectric parameters of the soil under different conditions. The results from this study confirm the potential of microwave reflectometry for moisture monitoring and contamination detection.peer-reviewe

GPR and IRT Tests in two Historical Buildings in Gravina in Puglia

This paper describes a noninvasive investigation conducted in two important churches, namely the Cathedral of Santa Maria Assunta and the church Santa Croce, both placed in Gravina in Puglia (close to Bari, southern Italy). The church of Santa Croce, now deconsecrated, lies below the Cathedral. Therefore, indeed the two churches constitute a unique building body. Moreover, below the church of Santa Croce there are several crypts, only partially known. The prospecting was performed both with a pulsed commercial GPR system and with a prototypal reconfigurable stepped frequency system. The aim was twofold, namely to achieve some information about the monument and to test the prototypal system. The GPR measurements have been also integrated with an IRT investigation performed on part of the vaulted ceiling of the church of Santa Croce, in order to confirm or deny a possible interpretation of some GPR results

COST Action TU1208 – Working Group 1 – Design and realisation of Ground Penetrating Radar equipment for civil engineering applications

This work aims at presenting the main results achieved by Working Group (WG) 1 "Novel Ground Penetrating Radar instrumentation" of the COST (European COoperation in Science and Technology) Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar" (www.cost.eu, www.GPRadar.eu). The principal goal of the Action, which started in April 2013 and is ending in October 2017, is to exchange and increase scientific-technical knowledge and experience of Ground Penetrating Radar techniques in civil engineering, whilst promoting throughout Europe the effective use of this safe non-destructive technique. The Action involves more than 300 Members from 28 COST Countries, a Cooperating State, 6 Near Neighbour Countries and 6 International Partner Countries

Proximity remote sensing : preliminary results at the Batia Church (Tortorici, Sicily)

The paper presents the results of scientific investigations carried out at the Batia Church located in the small village of Tortorici (Messina, Sicily). We performed several geophysical surveys and reconstruct 2D and 3D digital models of the monument using digital photogrammetry. From the 3D model accurate digital elevation models. A detail mapping was carried out using the derived 3D digital model identifying mayor fractures as well as quantifying the extent of original pain and the modern interventions.peer-reviewe

Broadband measurements of soil complex permittivity

Agriculture is a major consumer of freshwater and is often associated with low water productivity. To prevent drought, farmers tend to over-irrigate, putting a strain on the ever-depleting groundwater resources. To improve modern agricultural techniques and conserve water, quick and accurate estimates of soil water content (SWC) should be made, and irrigation timed correctly in order to optimize crop yield and water use. In this study, soil samples common to the Maltese Islands having different clay, sand, and silt contents were, primarily, investigated to: (a) deduce whether the dielectric constant can be considered as a viable indicator of the SWC for the soils of Malta; (b) determine how soil compaction affects the dielectric constant measurements; and (c) to create calibration curves to directly relate the dielectric constant and the SWC for two different soil types of low and high density. The measurements, which were carried out in the X-band, were facilitated by an experimental setup comprising a two-port Vector Network Analyzer (VNA) connected to a rectangular waveguide system. From data analysis, it was found that for each soil investigated, the dielectric constant increases notably with an increase in both density and SWC. Our findings are expected to aid in future numerical analysis and simulations aimed at developing low-cost, minimally invasive Microwave (MW) systems for localized SWC sensing, and hence, in agricultural water conservation. However, it should be noted that a statistically significant relationship between soil texture and the dielectric constant could not be determined at this stage.peer-reviewe

GPR and passive seismic investigations in the church of Santa Maria delle Grazie at Campi Salentina (Lecce, Italy)

In the present contribution we propose the results of an integrated measurement campaign including ground penetrating radar and passive seismic data achieved in the church of Santa Maria delle Grazie at Campi Salentina, a town close to Lecce, in southern Italy. The passive seismic results corroborate the interpretation of the main (quite numerous at it will be shown) anomalies identified thanks to the GPR investigation.peer-reviewe