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GPR (Ground Penetrating Radar) Time Slices in Archaeological Prospection
... It is well documented that archaeological prospecting initially uses geophysical methods, because they are non-invasive, relatively rapid to acquire and inexpensive (Brizzolari et al. 1992;Goodman et al. 1995;Neubauer 2004). Recently, the use of geophysical methods has increased, due to an improvement in automatical acquisition systems and the increased speed of personal computers, which permits the employment of advanced inversion algorithms. ...
... These techniques are able to provide improved target resolutions in terms of the dimensions and shape of the buried structures. (Conyers and Goodman 1997;Tsokas et al. 1995;Polymenakos et al. 2004). Magnetic surveys are able to recognise differences in terms of magnetic susceptibility that could be due to the thermo-remanent magnetism of cealed features which are seen as sources of anomalies of natural fields or of man made structures (Piro et al. 2001a). ...
... These maps, referred to time slices or as amplitude maps, provide easy visualisations of the location, depth, size and shape of the radar anomalies. Mapping the reflected radar energy can help to create useful information that can sometimes mirror the general archaeological site plans obtained from invasive excavation (Goodman et al. 1995;Piro et al. 2003). To compute horizontal time slices, the employed software compares amplitude variations within traces that were recorded within a defined time window. ...
In the last few years, the location and characterization of buried historical objects is a task that generally lends itself to geophysics, thanks to the improvement of automatically measuring geophysical systems and the development of specific software for inversion problems. Furthermore, the integration of different methods permits an interpretation in which potential misunderstandings and the uncertainty of results can be reduced. The aim of the present work was to detect buried structures in an unexplored area of a Sabine Necropolis (700‐300 B.C.) located in the area of the National Research Council (at Montelibretti, Rome). During the survey, three different geophysical techniques have been employed; fluxgate gradiometry, Electrical Resistivity Tomography and Ground‐Penetrating Radar. The results are compared, integrated and interpreted indicating location of unknown buried tombs.
An additional objective of this study consisted of testing new finite element modelling routines that have been integrated into the inversion algorithm developed by the authors in the past years, and, to compare the 2D inversion results with the ones achieved with the 3D Finite element inversion software ERTLab.
Finally, the interpreted geophysical results have been verified through archaeological direct excavation in 2005, which have confirmed the location, dimensions and shape of the buried structure (tomb).
... It is well documented that archaeological prospecting initially uses geophysical methods, because they are non-invasive, relatively rapid to acquire and inexpensive (Brizzolari et al. 1992;Goodman et al. 1995;Neubauer 2004). Recently, the use of geophysical methods has increased, due to an improvement in automatical acquisition systems and the increased speed of personal computers, which permits the employment of advanced inversion algorithms. ...
... These techniques are able to provide improved target resolutions in terms of the dimensions and shape of the buried structures. (Conyers and Goodman 1997;Tsokas et al. 1995;Polymenakos et al. 2004). Magnetic surveys are able to recognise differences in terms of magnetic susceptibility that could be due to the thermo-remanent magnetism of cealed features which are seen as sources of anomalies of natural fields or of man made structures (Piro et al. 2001a). ...
... These maps, referred to time slices or as amplitude maps, provide easy visualisations of the location, depth, size and shape of the radar anomalies. Mapping the reflected radar energy can help to create useful information that can sometimes mirror the general archaeological site plans obtained from invasive excavation (Goodman et al. 1995;Piro et al. 2003). To compute horizontal time slices, the employed software compares amplitude variations within traces that were recorded within a defined time window. ...
... Since the 3D C-scan was first utilised in the 1990s, the process of C-scan generation has been gradually standardised [15]. Traditionally, the parameters were mainly based on the experience of operators, which led to inevitable human bias in the imaging results and created difficulties in determining whether a subsurface C-scan was an accurate representation of underground reality, as the choice of parameter settings may result in completely different representations [16]. ...
... Remote Sens. 2023,15, 1309 ...
The three-dimensional (3D) ground-penetrating radar (GPR) has been widely applied in subsurface surveys and imaging, and the quality of the resulting C-scan images is determined by the spatial resolution and visualisation contrast. Previous studies have standardised the suitable spatial resolution of GPR C-scans; however, their measurement normalisation remains arbitrary. Human bias is inevitable in C-scan interpretation because different visualisation algorithms lead to different interpretation results. Therefore, an objective scheme for mapping GPR signals after standard processing to the visualisation contrast should be established. Focusing on two typical scenarios, a reinforced concrete structure and an urban underground, this study illustrated that the essential parameters were greyscale thresholding and transformation mapping. By quantifying the normalisation performance with the integration of image segmentation and structural similarity index measure, a greyscale threshold was developed in which the normalised standard deviation of the unit intensity of any surveyed object was two. A transformation function named “bipolar” was also shown to balance the maintenance of real reflections at the target objects. By providing academia/industry with an object-based approach, this study contributes to solving the final unresolved issue of 3D GPR imaging (i.e., image contrast) to better eliminate the interfering noise and better mitigate human bias for any one-off/touch-based imaging and temporal change detection.
... A sequence of high-quality C-scans with accurate geo-referencing is essential for correctly imaging underground. However, its first use was in the 1990s (Goodman et al. 1995;Lai et al. 2018a). The parameters used for the generation of slices are mainly determined by the experience of operators, leading to inevitable human bias (Millington and Cassidy 2010) because the choice of different parameter settings may result in completely different images. ...
... GPR 3D imaging has been widely applied in diverse fields of civil engineering: for example, in mapping underground utilities (Birken et al. 2002;Lai et al. 2016;Metwaly 2015); measuring change of physical properties in materials (Kowalsky et al. 2005;Léger et al. 2014;Leucci et al. 2003); and inspecting structural conditions (Alani et al. 2013;Baker et al. 1997;Lai et al. 2012Lai et al. , 2013. Goodman et al. (1995) summarized the processing flow of 3D time-slice reconstruction from a series of radargrams (B-scans) and focused on three major steps: setting up the survey grid, cutting slices, and interpolation, as shown in Fig. 24.2. ...
The invisible and congested world of underground utilities (UU) is an indispensable mystery to the general public because their existence is invisible until problems happen. Their growth aligns with the continuous development of cities and the ever-increasing demand for energy and quality of life. To satisfy a variety of modern requirements like emergency or routine repair, safe dig and excavation, monitoring, maintenance, and upscaling of the network, two basic tasks are always required. They are mapping and imaging (where?), and diagnosis (how healthy?). This chapter gives a review of the current state of the art of these two core topics, and their levels of expected survey accuracy, and looks forward to future trends of research and development (Sects. 24.1 and 24.2). From the point of view of physics, a large range of survey technologies is central to imaging and diagnosis, having originated from electromagnetic- and acoustic-based near-surface geophysical and nondestructive testing methods. To date, survey technologies have been further extended by multi-disciplinary task forces in various disciplines (Sect. 24.3). First, it involves sending and retrieving mechanical robots to survey the internal confined spaces of utilities using careful system control and seamless communication electronics. Secondly, the captured data and signals of various kinds are positioned, processed, and in the future, pattern-recognized with a database to robustly trace the location and diagnose the conditions of any particular type of utilities. Thirdly, such a pattern-recognized database of various types of defects can be regarded as a learning process through repeated validation in the laboratory, simulation, and ground-truthing in the field. This chapter is concluded by briefly introducing the human-factor or psychological and cognitive biases, which are in most cases neglected in any imaging and diagnostic work (Sect. 24.4). In short, the very challenging nature and large demand for utility imaging and diagnostics have been gradually evolving from the traditional visual inspection to a new era of multi-disciplinary surveying and engineering professions and even towards the psychological part of human–machine interaction.
... However, from a review of a large number of research studies conducted in recent decades , it is obvious that 3D C-scans were first utilized in the 1990s (Goodman et al., 1995). The process of generating C-scans is still immature, and yet to be standardized. ...
... Lualdi et al. (2003) point out that system resolution and antenna positioning accuracy are vital for high-quality 3D GPR imaging, while denser measurements ensure that image degradation is minimized. For acquired data, Goodman et al. (1995) summaries the processing flow of 3D time-slice reconstruction from a series of radargrams (B-scans) and focuses on 3 major steps: setting up the survey grid, cutting slices and interpolation. These steps are reflected in the above mentioned research, but a rigorous workflow, as used in 2D processing (Jol, 2009), is still missing. ...
GPR has been widely acknowledged as an effective and efficient technique for imaging the subsurface. But the process of constructing 3D GPR images (C-scans) is still subjective and mainly relies upon the operator's knowledge and experience. This study reviews the parameters that affect GPR imaging quality: namely, profile spacing (PS), slice thickness (ST) and interpolations. Feature characteristics that have a crucial influence on imaging quality were also identified. Through conducting 25 carefully designed empirical experiments on concrete as well as subsurface structures, the relationship between 3D imaging parameters and feature characteristics were observed. A general workflow was derived for GPR C-scan generation, which is analogous to the typical signal processing steps used in 2D radargram signal processing (Jol, 2009). Empirical values in workflow were based on the retrieval of known ground-truth data and comparison with the processed images, i.e. the closest to reality. Unlike 2D processing, the workflow for 3D is feature-oriented and case-specific, and the proposed workflow gives guidelines on suitable ranges for 3 major parameters when used in a variety of applications. It was identified that feature shapes and the ratios of feature size to radar footprint are of vital importance. With the proposed flowchart, the often vague “survey experience” is parametrized and standardized, and the upper and lower limits governing the generation of objective and trustworthy 3D GPR images are defined. This workflow for GPR 3D slice imaging also paves the way for GPR feature extraction and change detection commonly adopted in remote sensing.
... Sample spacing is a limitation that determines the size of archaeological features able to be detected. This can be resolved by ensuring that the interval between data points should be no greater than half the size of the smallest feature to be detected (Goodman et al., 1995;Conyers and Goodman, 1997;Kvamme, 2003). A global positioning system (GPS) survey, using a GPS Leica TM Viva in differential configuration, was performed to position the investigated area and to orientate the resulting models with respect to the excavated features of the villa. ...
... For this reason, only the transverse and longitudinal B-scans at 200 MHz have been interpolated to produce a series of horizontal 'time slices' (C-scans) at various depths below the surface. The C-scans can provide information regarding the location, size, shape and depth of subsurface archaeological structures at a site (Goodman et al., 1995;Conyers and Goodman, 1997;Piro et al., 2002;Kvamme, 2003;Gaffney et al., 2004). ...
We report here a multimethod geophysical investigation of the Sant'Imbenia Roman villa archaeological site in northern Sardinia (Italy). The main objective of this study is optimizing a non-invasive approach to reconstruct rapidly the geometry of coastal sites. A hitherto unexplored area of approximately 700 m2, adjacent to excavations, was investigated using ground-penetrating radar (GPR) and electrical resistivity tomography (ERT) surveys. The Sant'Imbenia villa is close to the present-day shoreline and subject to very high erosion rates and burial. A comparison of the high-resolution GPR and ERT models was made, and their integrated results are discussed in terms of providing a more complete picture that would not be attainable using a single method. Geophysical analysis combined with archeological prospecting has revealed buried buildings north of the excavated part of the archaeological site. The results show that in this coastal environment ERT survey provided the most accurate reconstruction at the deeper wet levels of investigation. Copyright © 2014 John Wiley & Sons, Ltd.
... Capizzi et al. 2021;Bottari et al. 2022) and data were reorganised in timeslices (e.g. Goodman, Nishimura, and Rogers 1995). In order to obtain a threedimensional model of the electromagnetic reflectivity of the subsoil ( Figure 5), a code implemented in Matlab was used for the construction of the data matrix. ...
Misterbianco, located on the southern slope of Mt. Etna (eastern Sicily), was destroyed in the past by two catastrophic events that raised the old town to the ground. The first was the great eruption of 1669, whose lava front buried dozens of villages encountered along its path, entirely destroying the architectural heritage of Etna's southern flank. The second event was the disastrous 1693 Val di Noto earthquake, which caused major destruction throughout south-eastern Sicily, also damaging the few still standing buildings in the town. The GPR survey performed at this site, 350 years after the eruption, allowed a first attempt of planimetric reconstruction of the San Nicolò Church. Starting from the site history, we present the results of an integrated approach that involves history, volcanology and geophysics aimed at addressing future archaeological excavations for the protection of archaeological and monumental assets in a difficult setting as this volcanic environment.
... Among geophysical prospecting methods, magnetic and GPR surveys are used to effectively acquire information on the existence and size of underground cultural remains as well as geological layers (Bevan & Smekalova, 2013;De Giorgi et al., 2020;Shaaban et al., 2008). GPR surveys are also useful for exploring historical sites due to their high resolution at shallow depths (Abd El-Hafeez et al., 2017;Goodman et al., 1995;Kim & Oh, 2003;Leckebusch, 2003;Oh & Shin, 2004). In addition, an automatic continuous 3D GPR survey can detect anomalous zones, indicating the existence of historical remains (Kim et al., 2005). ...
Geophysical techniques such as electrical resistivity, ground penetrating radar (GPR), gravity, magnetic, and seismic surveys are useful for prospecting archaeological remains. In this study, we delineated the domain and underground structure of the Bonghwang earth castle and the Royal Palace of the Geumgwan Gaya Kingdom, using multiple geophysical surveys (magnetic, electromagnetic, GPR, and electrical resistivity). Based on the results, the Bonghwang earth castle was extended from a small hill branching from the northern end of the Bonghwangdae hill with a width of 20 m to the hill on the southeast end with a width of slightly over 40 m. The Royal Palace inside the Bonghwang earth castle was further explored using magnetic and GPR surveys. As a result low magnetic values are surrounded radially by high magnetic values at multiple independent locations in an irregular shape in the centre of the Royal Palace. In contrast, the high anomaly zone near the centre of the Royal Palace had a rectangular or ellipsoidal shape, necessitating a clear need for archaeological investigation and excavation in the future.
... Ground penetrating radar is one of the shallow geophysical methods which have got approval because images of the underground geometries can be given with high resolution [29], [30], [31]. The method has a reputation as one of the more complex archaeological geophysical methods because it involves the collection of large amounts of reflection data from numerous transects with grids, often producing massive three-dimensional databases [32]. ...
Ground-Penetrating Radar (GPR) can successfully image the buried archaeological findings
depending on changes in the electromagnetic features of the researched materials. The GPR
survey in the Akçakale (Kordyle) castle built in the 13th century was presented in this study.
The castle is located at Akçakale district of Trabzon province on the Eastern Black Sea Coast
of Turkey. The key focus of this research is to investigate whether there are archaeological
findings in the inner area of the castle with GPR. For this purpose, GPR data were collected
by using 250 and 500 MHz antennas at 95 transects within grid lengths ranging 30-50m
in the study area. Anomalies considered to be important by evaluating the filtered data
were marked on a sketch where the measurement lines are located. On this sketch, the
overlapping areas of the anomalies obtained from the data in different directions on the
measurement lines were shown by ellipses with red-cut as priority possible anomaly areas.
Possible archaeological structures were been successfully determined from 2D and 3D
images obtained GPR data in the study area. As a result, it has been suggested that
archaeological excavations which will be planned in the study area should be conducted
by considering these areas. After the excavations, archaeological findings which are
compatible with anomalies were found in the studied area. Thus, it was seen that successful results were obtained with the GPR method in the study area.
... Ground penetrating radar is one of the shallow geophysical methods which have got approval because images of the underground geometries can be given with high resolution [29], [30], [31]. The method has a reputation as one of the more complex archaeological geophysical methods because it involves the collection of large amounts of reflection data from numerous transects with grids, often producing massive three-dimensional databases [32]. ...
... Ground penetrating radar (GPR) is one of the most effective and efficient geophysical techniques for imaging the subsurface [1,2]. Three-dimensional (3D) GPR imaging (Cscan) is becoming increasingly popular because it reveals the subsurface environment [3] as slices that are readily understandable. The denser the grid spacing, the higher the accuracy of the survey result [4][5][6]. ...
Three-dimensional GPR imaging requires evenly and densely distributed measurements, ideally collected without the need for ground surface markings, which is difficult to achieve in large-scale surveys. In this study, a guidance system was developed to guide the GPR operator to walk along a predesigned traverse, analogous to the flight path design of an airborne drone. The guidance system integrates an auto-track total station unit (ATTS), and by estimating the real-time offset angle and distance, guidance corrections can be provided to the operator in real time. There are two advantages: (1) reduced survey time as grid marking on the ground is no longer needed and (2) accurate positioning of each traverse. Lab and field experiments were conducted in order to validate the guidance system. The results show that with the guidance system, the survey paths were better defined and followed in terms of feature connectivity and resolution of images, and the C-scans generated were closer to the real subsurface world.
... Further information on the suitability of geophysical methods to map archaeological sites are found in Conyers & Lucius (1996), Conyers & Goodman (1997), Conyers (2004Conyers ( , 2006Conyers ( , 2012, Conyers & Leckebusch (2010), Zhao et al. (2013) and Allen et al. (2017), whereas the applications of 2D and 3D ground-penetrating radar (GPR) for archaeological sites has been discussed by Goodman et al. (1995), Malagodi et al. (1996), Groenenboom et al. (2001) and Novo et al. (2008). These include the influence of data-acquisition parameters for generating 3D time slices, such as the spacing between profiles, spatial and temporal sampling intervals, and sampling frequency. ...
Any archaeological site, according to the Brazilian Federal Constitution, is a patrimony of the Union; consequently, when crimes against this cultural patrimony occur, it becomes the responsibility of the Federal Police of Brazil. In 2013, there was a complaint to the Brazilian Federal Public Prosecutor's Office about the depredation of an archaeological site and forced withdrawal of the indigenous people because of the construction of a multimodal port in the city of Guaíra, in the state of Paraná, in southern Brazil. Thus, the Technical–Scientific Sector of the Federal Police Department, in partnership with Brazilian universities, used standard geophysical methods such as ground-penetrating radar (GPR) to investigate and locate buried archaeological targets. This paper discusses the results of 2D and 3D investigations in the Tekoha Jevy indigenous village, located in Guaíra County. In the field, 32 parallel sections of GPR data were acquired using 250 and 700 MHz shielded antennas. The results showed several anomalies, two of which were subjected to field checks using excavations, which revealed several artefacts such as ceramic fragments associated with ancient indigenous occupations on the banks of the Paraná River.
... Ground penetrating radar is one of the shallow geophysical methods which have got approval because images of the underground geometries can be given with high resolution [29], [30], [31]. The method has a reputation as one of the more complex archaeological geophysical methods because it involves the collection of large amounts of reflection data from numerous transects with grids, often producing massive three-dimensional databases [32]. ...
Akcakale (Haldandoz) is a historic castle located at the Akcakale town of Trabzon province. It is thought that archeological findings may be this castle for it has a history of 800 years and hosted to many culture. In this paper, we aimed to make an archeogeophysics work by using ground penetrating radar (GPR) for finding any remains in these areas. In accordance with this purpose, GPR data was collected with 250 MHz and 500 MHz shielded antennas on 11 profiles parallel each others directed from east to west in study area. In this study, time slice maps were generated after processing steps applied the data. These images were examined and compared obtained for 250 MHz and 500 MHz antenna at different depths. According to depth changes by using these two antennas, similar high-amplitude anomalies are displayed. Also, three high amplitude anomalies have been found compared to depth of 1.16 m obtained from 250 MHz and 500 MHz antennas in these time slice maps. A test excavation proposed on the part of high amplitude reflection indicated as arrows on the time slice maps in the study area.
... In order to visualize the data, the positive envelope of the signal was computed. Several methods can be applied (Goodman, 1995). In the case of la Mina the magnitude of the data From archaeological prospection to communication using learning theory 4. In order to correct the edge discontinuity, a small area of 0.20m around the edge was blanked and the correspondent data were interpolated. ...
The research was placed at the confluence of three fields: Archaeological Geophysics, Archaeology and Learning Theory. The two latter were considered in order to improve the transmission process of archaeological geophysics results.
Archaeological Geophysics is based on the use of methods that measure the contrast in physical properties. It is applied to map the context of archaeological sites. The mapping helps with the management of the research. The outputs of Archaeological Geophysics projects are produced through a nested sequence of decisions and actions. The sequence was separated in three phases: field, data transformation and data finalisation. The field phase includes the design of the project and the data acquisition survey. The transformation phase is dedicated to the processing of the acquired data and to their interpretation. During the finalisation, the data and metadata of the project are archived and the results are transmitted to the end-user.
Geophysical results are not often integrated in the communication process of archaeological findings. The main hypothesis of the research was that this absence can be explained by failure situations that occur during any phase of a project. Failure situation can be explained by results with insufficient resolution, not adequately transformed or poorly transmitted. The main objective of the research was to propose solutions to identify and limit these failure situations in order to improve the final transmission of the results.
Three approaches were proposed. The transmission process was analysed considering the different Learning Theory currents. A behaviourist approach gave a linear understanding of the information. It is based on standards and clearly defined contents. Its main vector would be the technical report. The cognitive contribution was the diversification of the formats of transmission. In addition to the technical report, a graphical report, an animated sequence and a model of the results were systematically produced. This associated material was created taking into account the relation between text, image and sound in order to improve the understanding process. The model represented the constructivist current. It enables the end-user having a personalised experience of the created environment through increased control and interactivity.
The second approach was to describe in detail the workflow of an Archaeological Geophysics project. The description aimed to define control points that could favour a better quality of the produced material. Control points were defined at each phase. In the field phase they include (1) the use of questionnaire during the design of the project, (2) the production of a diagram stating the archaeological objectives, the used methods and their limitations and (3) an appropriate preparation of the environment of the site prior to the acquisition of the data. The control points of the transformation phase were (1) the characterisation of the acquisition noise, (2) the vectorisation of the results with associated attributes and (3) the production of synthetic maps. The finalisation phase should include (1) the metadata of the project, (2) several parallel formats of transmission of the results and (3) open source formats for the digital archive.
In the third approach, the combination of geophysical results with archaeological objects was considered. Three case studies were presented. In the first case study the digital model of the surface of a monumental artefact was combined with GPR data for the assessment of its state of preservation. In the second case study, the data of an intensive surface sampling survey were combined to geophysical surveys to characterise the sequence of occupation of a site. In the third case study archaeological excavations and geophysical results were integrated in one platform to document the destruction of a Roman settlement.
... Radar will generally detect features of a given size at a greater depth than other geophysical instruments. Using time slices, or amplitude slice mapping, reflections can be separated into horizontal slices, each corresponding to a distinct depth in the ground, upon which the intensity of reflections at that depth are mapped (Goodman et al., 1995). GPR surveys were conducted using a Geophysical Survey Systems, Inc. (GSSI) 3000 with a 400 MHz antenna over two 20 x 40 m areas (Figure 1) in the unplowed portion of the site. ...
Information on depth may be gained through the analysis of geophysical maps, by utilizing soundings, pseudosections, or time-slices, or via the application of downhole measurements. Various methods and techniques were compared at the Biesterfeldt site, a proto-historic earth-lodge village in the Northern Plains, USA. Both traditional and more experimental approaches were used, including ground-penetrating radar time slices and overlay analyses, a resistivity pseudosection, two- and three-dimensional magnetic and resistivity modelling, and downhole tests of magnetic susceptibility, magnetic viscosity, total magnetic field, capacitance and resistivity. A direct-push colour system, measuring the reflection of light over the red–green–blue (RGB) and near-infrared spectrum, provided another useful tool for mapping the depths of archaeological features and stratigraphic layers.
... The application of the GPR technique for determination of the geometric characteristics of the reference target, as proposed in the configuration of previously reported measures, defines a good starting point to search for a valid response to the proposed aims. The time slices (Goodman et al. 1995) for the reticles of permanent surfaces and the different times of sampling should be sufficient to define a direct correlation between the response of the radar signal and the geometric characteristics of the subterranean object. This first investigation attempt has been defined already, even in the early stages of data acquisition, some obvious problems actually affect the final result and therefore require special attention for their resolution. ...
Mycorrhizal symbiotic plants, soil suitability, temperature, and humidity are, by general consensus, considered decisive factors in truffle production. However, experimental approaches to define the environmental conditions that stimulate formation of truffle primordia and promote their growth to maturity have been lacking. By analysis of data of many atmospheric and soil parameters collected since 2009 within a Tuber melanosporum orchard, the trends of metabolic activity, detected as CO2 production in the soil, have been identified as the most reliable parameter to indicate the 'birth' of the truffle primordia. They seem to be produced when mycelial activity is intense and undergoes water stress, after which it resumes. About 6-18 days after recovery of metabolic activity, we could collect primordia of T. melanosporum. Many die or develop too early and consequently rot or are eaten by insect larvae. These events occur several times during summer and autumn, those that 'sprout' in late summer or later grow steadily and reach maturity. Using a particular ground-penetrating radar (GPR) setup to discriminate truffles, we could identify individual truffles in the soil after they have enlarged to at least 6 mm in diameter and follow their growth in volume and diameter over time. These two instrumental methods (CO2 sensor and GPR), although yet to be improved, open new important perspectives to better understand truffle biology and manage truffle orchards to support the newly acquired demonstration of the fundamental role of host plants for the nutrient transfer to the ectomycorrhiza-mycelium-fruiting body complex of T. melanosporum.
Ground Penetrating Radar (GPR) survey was conducted to detect historic unmarked graves from the period of the Civil War (1861–1865) at the Fairlawn Cemetery in Stillwater, Oklahoma. The GPR survey at the Fairlawn Cemetery will help preserve the unmarked historic graves if they exist or clear sections of the cemetery for possible expansion. GPR detection of historic graves are often a challenge as these graves are made of wooden boxes, bones and coffins, with no metal caskets or concrete burial vaults. It was even more challenging to detect unmarked graves in this study as the cemetery is covered with iron‐rich silty clay soil, which attenuates the GPR signals. We conducted the GPR survey along a grid consisting of 44 parallel 30‐m‐long profiles spaced at 50‐cm intervals using the 400‐MHz antenna. The acquired GPR data were processed as 2D profiles and produced a pseudo‐3D GPR volume to resolve the unmarked graves. Multiple features extracted from the pseudo‐3D volume at depths ranging from 0.7 to 1.3 m aligned along three north–south rows. Based on the dimensions, orientation, distribution and depth of burial of the anomalous features relative to the recent graves, we interpreted these features as unmarked graves. This study has demonstrated the GPR as an effective non‐invasive technique in detecting historical unmarked graves that contain no metal caskets or concrete burial vaults. This work will contribute not only to the science of historical archaeology but also to prehistorical archaeology, as caskets were not typically part of the prehistorical burials, and the modern‐day archaeology, particularly in the cases of mass graves in recent conflicts.
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