Ground Penetrating Radar Results Research Articles

Angled ground penetrating radar to detect and position reinforcement and bearing lengths within reinforced autoclaved aerated concrete planks

This article presents a methodology that can be used to identify and estimate the positions of features within the hidden bearing region of Reinforced Autoclaved Aerated Concrete (RAAC) roofing planks. The method requires the careful design of a dielectric filled wedge to hold a Ground Penetrating Radar (GPR) sensor at a fixed angle relative to the surface of RAAC planks to enable novel angled beam examination of the end bearing. Interpretation can be performed using time-of-flight and Fermat’s principle. The approach was experimentally trialed on in-situ RAAC ceiling planks within an active hospital estate with the results validated by conventional intrusive surveying techniques, demonstrating agreement with the GPR results.

Application of Georadar Method to Investigate shallow Artifacts for Al-Maabid Area in Babylon Archaeological City

Babylon, one of the most influential civilizations in Mesopotamia, significantly contributed to human history with its rich culture, advanced legal systems, and architectural marvels, serving as the capital of the Neo-Babylonian empire. This study aims to discover ancient Babylonian civilizational remains and artifacts, including artifacts and walls from an ancient Babylonian house near the Ishtar temple. A geophysical survey was carried out using ground penetrating radar (GPR), yielding promising preliminary results. It contributed to the Department of Antiquities' excavation campaign for potential antiquities in Babylon Governorate, which was regarded as a preliminary step before beginning extensive excavations. Accurate GPR results were displayed as radargrams, maps, and 3D VI visualization diagrams, providing a precise subsurface view of buried archaeological remains.

Applying Ground Penetrating Radar and Electrical Resistivity Tomography for the Detection of Archaeological Structures in a Pre‐Tarascan Classic‐Epiclassic Site, Tingambato, Michoacán, Mexico

ABSTRACTA survey was conducted to investigate buried archaeological remains at Tingambato, a pre‐Tarascan classic‐epiclassic archaeological site located in the north‐central part of the State of Michoacán in western Mexico, using ground‐penetrating radar (GPR) and electrical resistivity tomography (ERT). The aim of this study was to detect the foundations (ancient buried walls) and cavities (tombs), define the geometry of the foundations and correlate construction style and depth with relative chronological buried structures. The survey was carried out on two grids of 15 m × 37 m (Zona Verde) and 10.25 m × 36.5 m (Ballgame court), using a 200 MHz antenna for GPR and Schlumberger‐Wenner arrays for ERT. GPR 3D acquisition was carried out along parallel lines spaced 0.25 m apart in a single direction. In the first area, considering the geometric shape found at a depth of 1.35 m, we can assume the existence of a buried structure, probably wall remains. In the second area, a very diffractive zone coincides with a resistive anomaly (> 2000 ohm·m). In order to refine the GPR results, synthetic modelling and a comparison with real traces were carried out. The 1D GPR modelling allows us to precise the presence of a cavity with a rectangular cross section. Since the type of volcaniclastic avalanche deposits of the subsoil do not allow the formation of cavities of that size, we infer that it may be the remains of a tomb or an anthropogenic cavity.

Internal structures of the Last Glacial Period multi-phase cold-climate aeolian dunes, Moravian Sahara, Czechia

Aeolian dunes in the Moravian Sahara developed during at least two distinct cold periods of the Last Glacial Period (LGP). Their two-phase development was previously deduced solely from the different orientations of dune crests without knowing the dunes' internal structure. Therefore, the aim of this study is to reveal the internal structure of the multi-generational dune system, developing a relationship between these dunes and bedrock. A combination of data was obtained from boreholes and ground-penetrating radar (GPR). GPR profiles were measured in places where the boreholes were drilled to obtain high-resolution combination data. Furthermore, models of aeolian sediment thickness and ground-water level were made using a spatial interpolation method (ordinary kriging with spherical semivariogram model) to interpret the GPR results and to investigate a relationship between the bedrock and dune patterns. Internal dune structures confirm the hypothesis of multi-generational development of this dune field. In addition, the aeolian sediment distribution was influenced by the bedrock topography. Finally, this study confirms that a change in LGP atmospheric circulation over Central Europe is the main controlling factor in forming the Moravian Sahara dune field.

Reflection characteristics of typical road defects in 3D GPR images for collapse mitigation

Road collapses pose dangerous threats to traffic safety in urban cities. Typically, these collapses result from under-road defects such as cavities, loose soil, and voids. With the development of multi-channel 3D ground penetrating radar (GPR) systems, GPR has become a routine method for inspecting the subsurface conditions of roads. However, the reflection characteristics of hidden defects in 3D GPR results have not been well studied due to the complexity of urban road structures. Consequently, accurately detecting all subsurface defects in GPR survey areas remains challenging. In this paper, numerical models of road structures with typical types of hidden defects are constructed, and their reflection characteristics in GPR B-scan profiles and C-scan depth slices are analyzed. Then, the field results obtained using a car-mounted 3D GPR system are presented to confirm the reflection characteristics of these hidden defects. Finally, the reflections of manhole covers and underground pipelines, which are the most prevalent forms of clutter in GPR images in urban environments, are compared with those of hidden defects. The findings of this paper will facilitate the accurate interpretation of field 3D GPR data for road inspections and the mitigation of road collapse accidents.

Estimation of Coarse Root System Diameter Based on Ground-Penetrating Radar Forward Modeling

Root diameter is an important indicator of plant growth and development to a large extent. However, the field monitoring of these parameters is severely limited by the lack of appropriate methods, and some traditional methods may harm the plant and its growing environment. Ground-penetrating radar (GPR) is a new nondestructive detection method for underground root systems. A new method for the estimation of the diameter of coarse roots using GPR with 900 MHz frequency was proposed in this paper. First, a simulation model was established to simulate the root system under natural conditions, and the root diameter estimation model based on the scanning results of GPR was obtained. Secondly, by studying the influence of soil and root relative permittivity on the diameter estimation model, a method was found to devise a coarse root diameter estimation model under different soil and root conditions of relative permittivity. Thirdly, the applicability of the diameter estimation model to roots with different growth orientations was tested by simulating roots with different growth orientations. Finally, the practical applicability of the estimation method was verified by field experiments. The results suggest that the root diameter estimation model can be constructed by extracting the pixel distance (∆p) of waveform parameters from the 900 MHz scanning results. This method can be used to estimate the diameter of coarse roots with diameters of no less than 2 cm and a relative permittivity greater than 5, and to estimate the diameter of roots in any orientation and soil environment effectively. At the same time, the application in the field experiment also resulted in a good estimation effect. This method provides a new opportunity to achieve more reliable root diameter estimation in complex situations. The estimation of coarse root diameter provides an experimental basis and data support for the healthy growth of trees, and also provides some information for the study of coarse root ecology.

High‐Resolution Geological Information from Crosshole Ground Penetrating Radar in Clayey Tills

AbstractHeterogeneous glacial deposits dominate large parts of the Northern Hemisphere. In these landscapes, high‐resolution characterization of the geology is crucial for understanding contaminant transport. Geological information is mostly obtained from multiple boreholes drilled during a site investigation, but such point‐based data alone do not always provide the required resolution to map small‐scale heterogeneity between boreholes. Crosshole ground penetrating radar (GPR) is suggested as a tool for adding credible geological information between boreholes at contaminated site investigations in industrial sites where infrastructure, such as electrical installations, can pose a challenge to other geophysical methods. GPR data are sensitive to the dielectric permittivity and the bulk electrical conductivity, which can be related to the distribution of water content and sand/clay occurrences. Here we present a detailed crosshole GPR dataset collected at an industrial contaminated site in a clay till setting. The data are processed using a novel inversion approach where information on changes in the velocity and attenuation of the radar signal are obtained independently. The GPR results are compared to borehole logs, grain size analyses, and relative permeability data from the site. The GPR data analysis provided valuable information on the understanding of the lateral geological variability. A silt layer with a thickness of a few decimeters, likely important for flow characterization, was confirmed and resolved by GPR data. Our findings suggest that crosshole GPR has the potential for contributing with high‐resolution geological information by filling the data gap between boreholes, thereby becoming a relevant tool in contaminated site investigations.

Reconstructing the Geometry of the Yushu Fault in the Tibetan Plateau Using TLS, GPR and Trenching

Although geomorphic evidence and shallow geometry of active faults are significant for the understanding and assessing of fault activity and seismic hazards, it is challenging to acquire high-resolution topographic data and shallow geometry of the Yushu fault by conventional methods. Here, we present a case study to reconstruct the detailed surficial and subsurface geometry of the Yushu fault using terrestrial laser scanning (TLS), multi-frequency ground penetrating radar (GPR) and trenching. TLS was suitable for measuring the high-resolution three-dimensional (3D) topographic data of the fault. GPR surveys with different frequency antennas (25 MHz, 100 MHz, 250 MHz and 500 MHz) were conducted to image the shallow geometry of active faults at different depths and spatial resolutions. The typical groove landscape, parallel to surface traces of the fault, was clearly observed on the TLS-derived data. A ~40 m width narrow fault system and three faults were identified on the different frequency GPR profiles. Furthermore, faults F1 and F2 were supposed to be boundary faults but were sinistral-lateral strike-slip faults with a normal component, while fault F3 was inferred as the secondary fault. The western trench section, despite the limited investigation depth (~2 m), was well consistent with the 500 MHz GPR result, especially in the location of fault F2. Finally, a 3D surficial and subsurface model was established from the TLS-derived data and GPR data offering multi-sensor and multi-view spatial data to characterize and understand the fault’s kinematics and characteristics. In addition, the shallow geometry of the fault on the GPR results would be better interpreted with the help of the corresponding surficial data. The study results demonstrate that a combination of TLS, multi-frequency GPRs and trenching can be successfully used for reconstructing a detailed surficial and subsurface geometry of the Yushu fault. It will play an increasing role in comprehensive understanding and assessing fault behavior and seismic hazards, especially on the Tibetan Plateau and the adjacent area.

Integration of Terrestrial Laser Scanner (TLS) and Ground Penetrating Radar (GPR) to Characterize the Three-Dimensional (3D) Geometry of the Maoyaba Segment of the Litang Fault, Southeastern Tibetan Plateau

High-resolution topographic and stratigraphic datasets have been increasing applied in active fault investigation and seismic hazard assessment. There is a need for the comprehensive analysis of active faults on the basis of the correlating geomorphologic features and stratigraphic data. The integration of TLS and GPR was adopted to characterize the 3D geometry of the fault on the Maoyaba segment of Litang fault. The TLS was used to obtain the high-resolution topographic data for establishing the 3D surficial model of the fault. The 2D 250 MHz and 500 MHz GPR profiles were carried out to image the shallow geometry of the fault along four survey lines. In addition, the 3D GPR survey was performed by ten 2D 500 MHz GPR profiles with 1 m spacing. From the 2D and 3D GPR results, a wedge-shaped deformation zone of the electromagnetic wave was clearly found on the GPR profiles, and it was considered to be the main fault zone with a small graben structure. Three faults were identified on the main fault zone, and fault F1 and F3 were the boundary faults, while the fault F2 was the secondary fault. The subsurface geometry of the fault on the GPR interpreted results is consistent with the geomorphologic features of the TLS-derived data, and it indicates that the Maoyaba fault is a typical, normal fault. For reducing the environmental disruption and economic losses, GPR was the most optimal method for detecting the subsurface structures of active faults in the Litang fault with a non-destructive and cost-effective fashion. The 3D surface and subsurface geometry of the fault was interpreted from the integrated data of TLS and GPR. The fusion data also offers the chance for the subsurface structures of active faults on the GPR profiles to be better understood with its corresponding superficial features. The study results demonstrate that the integration of TLS and GPR has the capability to obtain the high-resolution micro geomorphology and shallow geometry of active faults on the Maoyaba segment of the Litang fault, and it also provides a future prospect for the integration of TLS and GPR, and is valuable for active fault investigation and seismic hazard assessment, especially in the Qinghai-Tibet Plateau area.

Applications and Analytical Methods of Ground Penetrating Radar for Soil Characterization in a Silvopastoral System

The use of ground penetrating radar (GPR) for soil characterization has grown rapidly in recent years due to substantial increases in computer processing power and advances in GPR methodologies. However, few studies have focused on applied GPR analysis for soil characterization and decision making in agricultural systems. In this study, we explored applications of some common qualitative and quantitative methods for GPR analysis and characterization of subsurface conditions in a silvopasture system. We analyzed GPR results using traditional visual interpretation methods to delineate depth to bedrock, clay layers, and other important soil features. Estimates of depth to bedrock correlated well with values measured in the field ([Formula: see text]), and estimates of depth to clay layers were marginally correlated with observed values ([Formula: see text]). We also extracted attributes from GPR images to train a random forest regression model to predict coarse fragment percentage and percent clay content. GPR attributes were found to be good predictors of soil coarse fragments, with an R2 value of 0.81 and root mean square error (RMSE) of 18.82 for test data. Our results demonstrate GPR can provide valuable information on subsurface features in silvopastoral systems. These results also suggest a strong potential for machine learning algorithms in GPR data analytics. Data generated using these methods could be integrated with or used to validate existing digital soil mapping methods and contribute to better understanding of subsurface characteristics for optimized soil management in silvopastoral systems.

A new method for measuring the relative dielectric constant of porous mixed media using GPR, and its application

Natural materials mostly consist of porous mixed media, the relative dielectric constant (RDC) of which is a variable. The RDC of measured materials is often simply estimated as a constant value for the purposes of ground-penetrating radar (GPR) detection, which is one of the reasons for the significant quantitative identification error of GPR results. Only by accurately measuring the RDC of porous mixed media to calibrate the electromagnetic wave velocity can accurate quantitative GPR identification results be obtained. However, the difficulty is how precisely to identify the feature points of GPR signal of the measured material. In this study, a model test was carried out in a laboratory setting on porous mixed media consisting of dry sand, dry loam, and limestone. A new method was then proposed to accurately measure the RDC of porous mixed media. On this basis, three stages of accurate measurements of GPR were proposed, namely, signal processing, wavelet analysis, and quantitative identification. Experimental results showed that the relative error rate between the measured value (5.555) and the theoretical value (7.250) of porous mixed media was 23.38%, and the relative error rate of the measured value obtained by the new method was reduced from 13.78% to 1.50% in respect of quantitative recognition of GPR. The proposed method offers both unique advantages in improving the detection accuracy of GPR and great market potential, especially for projects requiring the accuracy of non-destructive testing (NDT). In addition, this study also proposed potential methodological feasibility and research ideas for predicting the physical properties of measured materials by establishing sensitive regions within three-dimensional spaces in the future.

Implementation of an Artificial Intelligence Approach to GPR Systems for Landmine Detection

Artificial Neural Network (ANN) approaches are applied to detect and determine the object class using a special set of the UltraWideBand (UWB) pulse Ground Penetrating Radar (GPR) sounding results. It used the results of GPR sounding with the antenna system, consisting of one radiator and four receiving antennas located around the transmitting antenna. The presence of four receiving antennas and, accordingly, the signals received from four spatially separated positions of the antennas provide a collection of signals received after reflection from an object at different angles and, due to this, to determine the location of the object in a coordinate system, connected to the antenna. We considered the sums and differences of signals received by two of the four antennas in six possible combinations: (1 and 2, 1 and 3, 2 and 3, 1 and 4, etc.). These combinations were then stacked sequentially one by one into one long signal. Synthetic signals constructed in such a way contain many more notable differences and specific information about the class to which the object belongs as well as the location of the searched object compared to the signals obtained by an antenna system with just one radiating and one receiving antenna. It therefore increases the accuracy in determining the object’s coordinates and its classification. The pulse radiation, propagation, and scattering are numerically simulated by the finite difference time domain (FDTD) method. Results from the experiment on mine detection are used to examine ANN too. The set of signals from different objects having different distances from the GPR was used as a training and testing dataset for ANN. The training aims to recognize and classify the detected object as a landmine or other object and to determine its location. The influence of Gaussian noise added to the signals on noise immunity of ANN was investigated. The recognition results obtained by using an ANN ensemble are presented. The ensemble consists of fully connected and recurrent neural networks, gated recurrent units, and a long-short term memory network. The results of the recognition by all ANNs are processed by a meta network to provide a better quality of underground object classification.

Interdisciplinary Investigations of the Neolithic Circular Ditch Enclosure of Velm (Lower Austria)

Middle Neolithic circular enclosures, known as Kreisgrabenanlage (KGA), are the oldest known monumental sites in Central Europe, dating roughly to 4850–4600/4500 BC. These large prehistoric monuments are mainly discovered by aerial archaeology and have been investigated by geophysical prospection and archaeological excavations since the 1960s. The site of Velm (Lower Austria) was discovered by aerial photographs in 2001. Due to its unusual location on a flat gravel plateau, the enclosure has become the object of intensive interdisciplinary research in recent years. In 2016, two motorized ground-penetrating radar (GPR) surveys were conducted, resulting in a detailed three-dimensional dataset visualizing the circular ditches, palisades and dwellings of an adjacent settlement. The high contrast between the gravel sediments and the humic earthen backfill of the ditches, palisades and individual postholes resulted in a highly detailed visualization of the Middle Neolithic monument. Based on this survey, selected structures were investigated by targeted archaeological excavations to evaluate the GPR results and to take samples for radiocarbon dating. This paper presents a synopsis of all the methods used. An integrated interpretation of aerial photo information, magnetometry and GPR is conducted, and it is shown to what extent these could be verified by the targeted archaeological excavation. By a detailed analysis of all applied archaeological prospection methods, it is now possible to interpret the monument in its entirety and confirm its dating to the Middle Neolithic Lengyel cultural complex.

Improving the accuracy of pavement structural quality assessment by correcting numerical hypothetical model of modulus Back-Calculation through GPR

This study shows a pavement structural quality assessment method combined with Ground Penetrating Radar (GPR) and Falling Weight Deflectometer (FWD). Through the detection results of GPR on the internal structure of pavement, we corrected the thickness, initial modulus range, and Poisson’s s ratio of the numerical hypothetical model in modulus back-calculation. We observed that the corrected numerical hypothetical model had significantly improved the accuracy of modulus back-calculation results. At the same time, we also compared the influence degree of the change in each structural parameter on the modulus back-calculation results. In addition, we used 3D-Move Analysis to analyze the stress and strain state of each structural layer of the pavement under various structural parameter combinations. The results show that the correction of structural parameters based on the GPR detection results of each structural layer significantly improved the accuracy of the modulus back-calculation results. At the same time, the accuracy of stress and strain calculation results of each structural layer was indirectly improved. It is suggested to implement this method for pavement structure quality assessment.

Unmanned Ground Vehicle Equipped with Ground Penetrating Radar for Improvised Explosives Detection

The article presents some objectives and results of the European Defense Agency Program on: Improvised Explosive Devices Detection (IEDDET Program)[1]. The goal of the article is to describe the work, results and recommendations regarding Unmanned Ground Vehicle (UGV) and Ground Penetrating Radar (GPR) - contributions within the MUSICODE project. Its scope and goals were presented, which are in line with the objectives of the IEDDET Program taking into consideration that the recommendations (for UGV and GPR) are related to the goals, not the results of MUSICODE project. There were described scenarios and the resulting changes in the structure implemented in the UGV - the FLORIAN robot which served as a sensors carrier including Ground Penetrating Radar (GPR). The main focus of the article is to find the answer to the research question: what is an impact of using the GPR to be mounted on the UGV to detect improvised explosive devices (IEDs) on the UGV construction and the GPR results. The structure of this radar was described and examples of tests results were presented. The summary presents recommendations for the construction of an unmanned land platform to carry sensors used in the work carried out in the MUSICODE project and conclusions regarding GPR, resulting from the experiences gained under the IEDDET Program.

Evaluating the Properties of Railway Ballast Using Spectral Analysis of Ground Penetrating Radar Signal Based on Optimized Variational Mode Decomposition

Ground penetrating radar (GPR) has been widely applied in the assessment of railway ballast conditions (fouling, moisture) by using the spectrum of the tested GPR signal. However, the drawbacks of the low time‐frequency resolution and mode mixing prevent the traditional spectrum methods from a wide application. This paper uses the advanced time‐frequency analysis of GPR signal based on optimized variational mode decomposition to extract the features of ballast. The new approach overperforms the conventional frequency spectrum methods of GPR signal processing by giving a clear and quantitative assessment of ballast signals. Experimental results of GPR with dry and wet fouled ballasts demonstrate that, by comparison with the feature extraction method of conventional spectrum methods such as spectrogram and wavelet, the feature extraction method based on the optimized VMD has much better separability and quantitative identification capability.

Ground penetrating radar surveys in the archaeological area of Augusta Bagiennorum: Comparisons between geophysical and archaeological campaigns

AbstractGeophysical methods, and particularly ground penetrating radar (GPR), have been increasingly applied as a preliminary mapping tool to guide archaeological excavations. Direct comparisons between geophysical and archaeological features are however not always systematically performed given the different time spans, covered areas, acquisition and processing approaches of the surveys. A critical comparison between geophysical and archaeological results is here proposed on a test site within the archaeological area of Augusta Bagiennorum (NW Italy). Three rectangular sectors covering an area of approximately 2325 m2 were investigated with high‐density GPR profiles and compared with both historical and new archaeological excavations. The GPR amplitude and attribute analyses highlight the effectiveness of geophysical prospections in identifying buried linear (i.e., walls) and localized (e.g., pillars or columns) archaeological remains. The recent archaeological excavations fully confirm the interpretation of the GPR results. Historical archaeological trenches, filled with coarse material after the excavation, are also found to generate strong anomalies in the GPR amplitude, similar to the ones of the buried structures, but with irregular contours and oblique orientations with respect to Roman remains. The GPR prospections also highlight interesting buried elements in unexplored areas, supporting important archaeological interpretations about the spatial configuration of the Roman city. The results help to recognize sectors with significant and well‐preserved buried remains that can be brought to light in the future to promote heritage conservation and enhancement at the site.

Monitoring of simulated clandestine graves of dismembered victims using UAVs, electrical tomography, and GPR over one year to aid investigations of human rights violations in Colombia, South America.

In most Latin American countries, there are significant numbers of missing people and forced disappearances, over 120,000 in Colombia alone. Successful detection of shallow buried human remains by forensic search teams is difficult in varying terrain and climates. Previous research has created controlled simulated clandestine graves of murder victims to optimize search techniques and methodologies. This paper reports on a study on controlled test site results over four simulated dismembered victims' clandestine graves as this is sadly a common scenario encountered in Latin America. Multispectral images were collected once post-burial, electrical resistivity surveys were collected 4 times, and ground penetrating radar (GPR) surveys were collected three times up to the end of the 371day survey monitoring period. After data processing, results showed that the multispectral data set could detect the simulated clandestine and control graves, with electrical resistivity imaging relative high resistances over some of the simulated graves but not over the empty control graves. GPR results showed good imaging on the Day 8surveys, medium imaging on the Day 294surveys, and medium to good imaging on the Day 371surveys. Study implications suggest that, while clandestine graves of dismembered homicide victims would likely result in smaller-sized graves when compared to graves containing intact bodies, these graves can still potentially be detected using remote sensing and geophysical methods.

Application of high-power ground-penetrating radar antennas with different frequencies to quickly locate the upper breakpoint of active buried faults in an urban area in the Datong basin (northern China)

Due to the difficulty in detecting the upper breakpoint of active buried faults, high-resolution detection of active buried faults in urban areas is very important for urban planning and disaster risk mitigation. The seismic reflection technique is the most common technique used to image faults at depth, but it is difficult to precisely locate the upper breakpoint of active buried faults. Ground-penetrating radar (GPR) provides high-resolution imaging in ultrashallow exploration, but the penetration depth of traditional GPR is shallow. In this work, we conducted six GPR surveys with multifrequency (25 MHz, 50 MHz and 100 MHz) and high-power GPR antennas across the possible range of the Shuiyu fault based on seismic reflection results. We obtained the trace of the Shuiyu fault within 45 m of the surface in Datong city, and the fault was found to dip approximately 70–80° to the SE. According to the GPR results, we selected a location for trenching and excavated one trench across the Shuiyu fault. The trench results verified the accuracy of the fault imaging in the GPR profiles and helped to interpret the stratigraphic information in the GPR profiles. In the accurate detection of active buried faults in other urban areas, the seismic reflection method can be used to determine the main strike of faults at depth, and then GPR can be used to detect the near-surface distribution of the faults in detail and guide trench location selection. The application of high-power GPR antennas with different frequencies in the fast detection of the upper breakpoint of active buried faults in urban areas is of great significance to earthquake hazard analysis and urban planning in Datong city.

Ground-penetrating radar and electrical resistivity tomography surveys at the Cerrate Abbey (Lecce, Italy)

The results of the geophysical surveys carried out in 2019 in the Abbey of Santa Maria di Cerrate (Lecce) are presented in this paper. The objective of this study was to achieve a better knowledge of the site, since it was only partially investigated by small archaeological excavation samples. The geophysical measurements were conducted inside and outside the church in order to identify buried ancient structures, using both the georadar and geoelectrical survey methodologies. The results of GPR (ground-penetrating radar), ERT (electrical resistivity tomography) and IP (induced polarisation) were jointly analysed with archaeological data already known and were georeferenced on the general plans of the site in order to obtain an overall view of the anomalies detected by geophysical instrumentation and probably linked to buried ancient structures.