scholarly journals Integration of high resolution geophysical methods. Detection of shallow depth bodies of archaeological interest

1998 ◽  
Vol 41 (3) ◽  
Author(s):  
F. Cammarano ◽  
P. Mauriello ◽  
D. Patella ◽  
S. Piro ◽  
F. Rosso ◽  
...  
Keyword(s):  
Methodological Approach ◽  
Geophysical Methods ◽  
Test Site ◽  
Governing Parameter ◽  
Near Surface ◽  
Magnetic Methods ◽  
Acquisition Mode ◽  
2D Data ◽  
Ground Penetrating ◽  
Self Potential

A combined survey using ground penetrating radar, self-potential, geoelectrical and magnetic methods has been carried out to detect near-surface tombs in the archaeological test site of the Sabine Necropolis at Colle del Forno, Rome, Italy. A 2D data acquisition mode has been adopted to obtain a 3D image of the investigated volumes. The multi-methodological approach has not only demonstrated the reliability of each method in delineating the spatial behaviour of the governing parameter, but mainly helped to obtain a detailed physical image closely conforming to the target geometry through the whole set of parameters involved.

scholarly journals Investigating the Performance of Bi-Static GPR Antennas for Near-Surface Object Detection

Sensors ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 170 ◽  
Author(s):  
Xianyang Gao ◽  
Frank J. W. Podd ◽  
Wouter Van Verre ◽  
David J. Daniels ◽  
Anthony J. Peyton
Keyword(s):  
Ground Penetrating Radar ◽  
Input Impedance ◽  
Test Site ◽  
Late Time ◽  
Near Surface ◽  
Object Depth ◽  
Ground Penetrating ◽  
Antenna Input ◽  
Surface Object ◽  
Bow Tie

Antennas are an important component in ground penetrating radar (GPR) systems. Although there has been much research reported on the design of individual antennas, there is less research reported on the design of the geometry of bi-static antennas. This paper considers the effects of key parameters in the setup of a GPR head consisting of a bi-static bow-tie pair to show the effect of these parameters on the GPR performance. The parameters investigated are the antenna separation, antenna height above the soil, and antenna input impedance. The investigation of the parameters was performed by simulation and measurements. It was found when the bi-static antennas were separated by 7 cm to 9 cm and were operated close to the soil (2 cm to 4 cm), the reflected signal from a near-surface object is relatively unaffected by height variation and object depth. An antenna input impedance of 250 Ω was chosen to feed the antennas to reduce the late-time ringing. Using these results, a new GPR system was designed and then evaluated at a test site near Benkovac, Croatia.

Correlation between near-surface electromagnetic soil parameters and early-time GPR signals: An experimental study

Geophysics ◽  
2007 ◽  
Vol 72 (2) ◽  
pp. A25-A28 ◽  
Author(s):  
Elena Pettinelli ◽  
Giuliano Vannaroni ◽  
Barbara Di Pasquo ◽  
Elisabetta Mattei ◽  
Andrea Di Matteo ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Early Time ◽  
Test Site ◽  
Time Domain Reflectometry ◽  
Soil Parameters ◽  
Time Interval ◽  
Near Surface ◽  
Novel Approach ◽  
Natural Test ◽  
Ground Penetrating

We explore a new approach to evaluate the effect of soil electromagnetic parameters on early-time ground-penetrating radar (GPR) signals. The analysis is performed in a time interval which contains the direct airwaves and ground waves, propagating between transmitting and receiving antennas. To perform the measurements we have selected a natural test site characterized by very strong lateral gradient of the soil electrical properties. To evaluate the effect of the subsoil permittivity and conductivity on the radar response we compare the envelope amplitude of the GPR signals received in the first [Formula: see text] within [Formula: see text]-wide windows, with the electrical properties ([Formula: see text] and [Formula: see text]) determined using time-domain reflectometry (TDR). The results show that the constitutive soil parameters strongly influence early-time signals, suggesting a novel approach for estimating the spatial variability of water content with GPR.

scholarly journals Landslide investigations using the geoelectrical scanning method and ground penetrating radar: Case studies

Tehnika ◽  
2021 ◽  
Vol 76 (4) ◽  
pp. 419-425
Author(s):  
Filip Arnaut ◽  
Branislav Sretenović
Keyword(s):  
Ground Penetrating Radar ◽  
Geophysical Methods ◽  
Relevant Information ◽  
Electromagnetic Signal ◽  
Near Surface ◽  
Scanning Method ◽  
Low Resistivity ◽  
Geotechnical Investigations ◽  
Landslide Body ◽  
Ground Penetrating

Geotechnical investigations of landslides for future mitigation are a complex task. To obtain relevant information, various geophysical methods are used, with varying degrees of success. The geoelectrical scanning method, also known as Electrical Resistivity Tomography (ERT) has been successfully applied in several locations in Serbia in the las three decades. The geoelectrical scanning method was used during investigations of landslides: Umka, Lukovska banja, Tara, and Trandžament, while both geoelectrical scanning and Ground Penetrating Radar (GPR) were utilized at the Trandžament landslide. The achieved results from both methods are mutually correlated at the Trandžament landslide. Correlation of GPR data with geoelectrical scanning data was only possible since there were no nearsurface low resistivity zones in the Trandžament landslide body. Otherwise, electromagnetic signal attenuation would be high in the presence of near-surface low resistivity zones, and a quality signal would be impossible to detect at the receiving antenna.

scholarly journals GPR imaging of traffic compaction effects on soil structures

2021 ◽  
Author(s):  
Akinniyi Akinsunmade
Keyword(s):  
Test Site ◽  
Survey Method ◽  
Natural Setting ◽  
Soil Horizons ◽  
Near Surface ◽  
Soil Structures ◽  
Geophysical Technique ◽  
Ground Penetrating ◽  
Soil Subsurface ◽  
Made In

AbstractSpatial and depth variability of soil characteristics greatly influence its optimum utilization and management. Concealing nature of soil subsurface horizons has made the traditional soil investigations which rely on point information less reliable. In this study, an alternative use of ground penetrating radar (GPR)—a near-surface geophysical survey method—was tested to address the shortcomings. The focus of the study was on assessment of characteristics variability of soil layers at a test site and evaluation of effects of compaction caused by machinery traffics on soil. GPR methods utilize electromagnetic energy in the frequency range of 10 MHz and 3.0 GHz. Fourteen profiles GPR data were acquired at the test site-a farmland in Krakow, Poland. Compaction on parts of the soil was induced using tractor movements (simulating traffic effects) at different passes. Data were processed using basic filtering algorithms and attributes computations executed in Reflexw software. Attempt made in the study was on use of GPR geophysical technique for soil assessment. The method allows delineation of the soil horizons which depicts characteristic depth changes and spatial variability within the horizons. Moreover, traffic effects that caused compaction on parts of the soil horizons were discernable from the GPR profile sections. Thus, similar densification like hardpan that may develop in natural setting can be investigated using the method. The results have shown the suitability of the method for quick, noninvasive and continuous soil investigation that may also allow assessment of temporal soil changes via repeated measurement.

scholarly journals Near surface geophysics techniques and geomorphological approach to reconstruct the hazard cave map in historical and urban areas

2010 ◽  
Vol 24 ◽  
pp. 35-44 ◽  
Author(s):  
M. Lazzari ◽  
A. Loperte ◽  
A. Perrone
Keyword(s):  
Urban Areas ◽  
Electrical Resistivity Tomography ◽  
Methodological Approach ◽  
Progressive Increase ◽  
Urban Context ◽  
Resistivity Tomography ◽  
Near Surface ◽  
Near Surface Geophysics ◽  
Ground Penetrating ◽  
Geomorphological Analysis

Abstract. This work, carried out with an integrated methodological approach, focuses on the use of near surface geophysics techniques, such as ground penetrating radar and electrical resistivity tomography (ERT), and geomorphological analysis, in order to reconstruct the cave distribution and geometry in a urban context and, in particular, in historical centres. The interaction during recent centuries between human activity (caves excavation, birth and growth of an urban area) and the characters of the natural environment were the reasons of a progressive increase in hazard and vulnerability levels of several sites. The reconstruction of a detailed cave map distribution is the first step to define the anthropic and geomorphological hazard in urban areas, fundamental basis for planning and assessing the risk.

scholarly journals A monitoring system for spatiotemporal electrical self-potential measurements in cryospheric environments

2020 ◽  
Vol 9 (2) ◽  
pp. 317-336
Author(s):  
Maximilian Weigand ◽  
Florian M. Wagner ◽  
Jonas K. Limbrock ◽  
Christin Hilbich ◽  
Christian Hauck ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Measurement System ◽  
Geophysical Methods ◽  
Early Warning Systems ◽  
Freezing And Thawing ◽  
Technical Application ◽  
Near Surface ◽  
Spatially Resolved ◽  
Noise Measurements ◽  
Self Potential

Abstract. Climate-induced warming increasingly leads to degradation of high-alpine permafrost. In order to develop early warning systems for imminent slope destabilization, knowledge about hydrological flow processes in the subsurface is urgently needed. Due to the fast dynamics associated with slope failures, non- or minimally invasive methods are required for inexpensive and timely characterization and monitoring of potential failure sites to allow in-time responses. These requirements can potentially be met by geophysical methods usually applied in near-surface geophysical settings, such as electrical resistivity tomography (ERT), ground-penetrating radar (GPR), various seismic methods, and self-potential (SP) measurements. While ERT and GPR have their primary uses in detecting lithological subsurface structure and liquid water/ice content variations, SP measurements are sensitive to active water flow in the subsurface. Combined, these methods provide huge potential to monitor the dynamic hydrological evolution of permafrost systems. However, while conceptually simple, the technical application of the SP method in high-alpine mountain regions is challenging, especially if spatially resolved information is required. We here report on the design, construction, and testing phase of a multi-electrode SP measurement system aimed at characterizing surface runoff and meltwater flow on the Schilthorn, Bernese Alps, Switzerland. Design requirements for a year-round measurement system are discussed; the hardware and software of the constructed system, as well as test measurements are presented, including detailed quality-assessment studies. On-site noise measurements and one laboratory experiment on freezing and thawing characteristics of the SP electrodes provide supporting information. It was found that a detailed quality assessment of the measured data is important for such challenging field site operations, requiring adapted measurement schemes to allow for the extraction of robust data in light of an environment highly contaminated by anthropogenic and natural noise components. Finally, possible short- and long-term improvements to the system are discussed and recommendations for future installations are developed.

Pseudo-3D imaging of a low-slip-rate, active normal fault using shallow geophysical methods: The Geleen fault in the Belgian Maas River valley

Geophysics ◽  
2008 ◽  
Vol 73 (1) ◽  
pp. B1-B9 ◽  
Author(s):  
Kris Vanneste ◽  
Koen Verbeeck ◽  
Toon Petermans
Keyword(s):  
Geophysical Methods ◽  
Slip Rate ◽  
Normal Fault ◽  
River Valley ◽  
High Resistivity ◽  
Near Surface ◽  
Precise Position ◽  
Roer Valley Graben ◽  
Ground Penetrating ◽  
Sediment Layers

In a detailed site survey for paleoseismic trenching, we applied shallow geophysical prospecting techniques, including ground-penetrating radar (GPR), electric resistivity tomography (ERT), and resistivity mapping to identify, locate, and visualize in 3D the Geleen fault, an active normal fault bordering the Roer Valley graben in northeast Belgium. Because of a low slip rate, the geomorphic expression of this fault is very faint in the relatively young deposits of the Maas River valley. ERT profiles show the fault as a broad, near-vertical anomaly characterized by sharp lateral resistivity contrasts, with an associated vertical offset of sediment layers. We observed offsets of [Formula: see text] and [Formula: see text] for the base and top, respectively, of a middle-late Pleistocene fluvial gravel layer. Shallow ERT and GPR profiles indicate that younger sediments are also affected by faulting, but the amount and sense of offset appear to be conflicting: ERT profiles show a near-surface, high-resistivity layer with an apparent reverse offset, and GPR profiles portray the fault as a sharp and laterally consistent disruption of reflectors, often without a clearly identifiable offset. Resistivity maps at different depths map the fault as a narrow, linear, lateral resistivity gradient matching the anomalies observed with other techniques. This method proved to be efficient in determining the precise position and orientation of dip-slip faults, and could potentially be very useful for the identification of lateral changes in fault geometry, such as splays and step-overs. Subsequent trenching confirmed the presence of a normal fault at the location predicted by the geophysical survey. Correlation with the sediments exposed on the trench walls demonstrated that, close to the surface, resistivity and dielectric permittivity contrasts mostly occur in a postdepositional soil, which developed differently on either side of the fault. This explains why shallow geophysical variations do not reflect the true fault offset.

Detection of the near surface structure through a multidisciplinary geophysical approach

2011 ◽  
Vol 3 (4) ◽  
Author(s):  
Eleni Kokinou ◽  
Apostolos Sarris
Keyword(s):  
Seismic Refraction ◽  
Geophysical Methods ◽  
Near Surface ◽  
The Road ◽  
Resistivity Method ◽  
Conductivity Anomalies ◽  
2D Resistivity Imaging ◽  
Limestone Rock ◽  
Ground Penetrating ◽  
2D Resistivity

AbstractThe present survey aimed to image the subsurface structure, including karstic voids, and to evaluate the extent of the heterogeneities that can result in potentially dangerous collapse of road segments overlying these features. A multidisciplinary geophysical approach (seismic refraction, frequency domain electromagnetic and ground penetrating radar) in combination with a detailed geological survey indicated the presence of tectonic faults as well as velocity and conductivity anomalies along an old road within the area of Akrotiri at Chania (Crete). Due to the presence of subsurface fuel pipes, perpendicular to the direction of the road, 2D resistivity imaging was excluded from the applied geophysical methods.Interpretation of the geophysical data revealed that the section of the road investigated overlies prominent voids attributed mostly to karst features. The conductivity and velocity anomalies are interpreted to indicate an area where the host limestone rock has been downthrown by faulting and associated karstification. The continuation of this fault zone was observed in the slope of the road during later excavations. Interpretation, using geographic information systems (GIS) to integrate data, allowed these controls and relationships to be understood and monitored. The above methodology was proved successful for areas where the application of resistivity method is not possible.

scholarly journals A monitoring system for spatiotemporal electrical self-potential measurements in cryospheric environments

2020 ◽  
Author(s):  
Maximilian Weigand ◽  
Florian M. Wagner ◽  
Jonas K. Limbrock ◽  
Christin Hilbich ◽  
Christian Hauck ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Water Flow ◽  
Measurement System ◽  
Geophysical Methods ◽  
Early Warning Systems ◽  
Freezing And Thawing ◽  
Technical Application ◽  
Near Surface ◽  
Noise Measurements ◽  
Self Potential

Abstract. Climate-induced warming increasingly leads to degradation of high-alpine permafrost. In order to develop early warning systems for imminent slope destabilization, knowledge about hydrological flow processes in the subsurface is urgently needed. Due to the fast dynamics associated with slope failures, non- or minimally invasive methods are required for cheap and timely characterization and monitoring of potential failure sites to allow in-time responses. These requirements can potentially be met by geophysical methods usually applied in near-surface geophysical settings, such as electrical resistivity tomography (ERT), ground penetrating radar (GPR), various seismic methods, and self-potential (SP) measurements. While ERT and GPR have their primary uses in detecting lithological subsurface structure and liquid water/ice content variations, SP measurements are sensitive to active water flow in the subsurface. Combined, these methods provide huge potential to monitor the dynamic hydrological evolution of permafrost systems. However, while conceptually simple, the technical application of the SP method in high-alpine mountain regions is challenging, especially if spatially resolved information is required. We here report on the design, construction, and testing phase of a multi-electrode SP measurement system aimed at characterizing surface runoff and melt-water flow at the Schilthorn, Bernese Alps, Switzerland. Design requirements for a year-round measurement system are discussed, the hardware and software of the constructed system, as well as test measurements are presented, including detailed quality assessment studies. On-site noise measurements and one laboratory experiment on freezing and thawing characteristics of the SP electrodes provide supporting information. It was found that a detailed quality assessment of the measured data is important for such challenging field site operations, requiring adapted measurement schemes to allow for the extraction of robust data in light of an environment highly contaminated by anthropogenic and natural noise components. Finally, possible short- and long-term improvements to the system are discussed and recommendations for future installations are developed.

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