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 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.

Vertical radar profiling: Combined analysis of traveltimes, amplitudes, and reflections

Geophysics ◽  
2014 ◽  
Vol 79 (4) ◽  
pp. H23-H35 ◽  
Author(s):  
Jens Tronicke ◽  
Göran Hamann
Keyword(s):  
Test Site ◽  
Direct Wave ◽  
Combined Analysis ◽  
Arrival Times ◽  
Traveltime Inversion ◽  
Velocity Models ◽  
Reflection Image ◽  
Geophysical Technique ◽  
Ground Penetrating ◽  
And Inversion

Vertical radar profiling (VRP) is a single-borehole geophysical technique, in which the receiver antenna is located within a borehole and the transmitter antenna is placed at one or various offsets from the borehole. Today, VRP surveying is primarily used to derive 1D velocity models by inverting the arrival times of direct waves. Using field data collected at a well-constrained test site in Germany, we evaluated a VRP workflow relying on the analysis of direct-arrival traveltimes and amplitudes as well as on imaging reflection events. To invert our VRP traveltime data, we used a global inversion strategy resulting in an ensemble of acceptable velocity models, and thus, it allowed us to appraise uncertainty issues in the estimated velocities as well as in porosity models derived via petrophysical translations. In addition to traveltime inversion, the analysis of direct-wave amplitudes and reflection events provided further valuable information regarding subsurface properties and architecture. The used VRP amplitude preprocessing and inversion procedures were adapted from ray-based crosshole ground-penetrating radar (GPR) attenuation tomography and resulted in an attenuation model, which can be used to estimate variations in electrical resistivity. Our VRP reflection imaging approach relied on corridor stacking, which is a well-established processing sequence in vertical seismic profiling. The resulting reflection image outlines bounding layers and can be directly compared to surface-based GPR reflection profiling. Our results of the combined analysis of VRP, traveltimes, amplitudes, and reflections were consistent with independent core and borehole logs as well as GPR reflection profiles, which enabled us to derive a detailed hydrostratigraphic model as needed, for example, to understand and model groundwater flow and transport.

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.

Imaging the internal structure of trunks via multiscale phase inversion of ground-penetrating radar data

2021 ◽  
pp. 1-53
Author(s):  
Lei Fu ◽  
Lanbo Liu
Keyword(s):  
Dielectric Constant ◽  
Internal Structure ◽  
Ground Penetrating Radar ◽  
Phase Inversion ◽  
Multiscale Approach ◽  
White Oak ◽  
Near Surface ◽  
Oak Tree ◽  
Ground Penetrating ◽  
Constant Distribution

Ground-penetrating radar (GPR) is a geophysical technique widely used in near-surface non-invasive detecting. It has the ability to obtaining a high-resolution internal structure of living trunks. Full wave inversion (FWI) has been widely used to reconstruct the dielectric constant and conductivity distribution for cross-well application. However, in some cases, the amplitude information is not reliable due to the antenna coupling, radiation pattern and other effects. We present a multiscale phase inversion (MPI) method, which largely matches the phase information by normalizing the magnitude spectrum; in addition, a natural multiscale approach by integrating the input data with different times is implemented to partly mitigate the local minimal problem. Two synthetic GPR datasets generated from a healthy oak tree trunk and from a decayed trunk are tested by MPI and FWI. Field GPR dataset consisting of 30 common shot GPR data are acquired on a standing white oak tree (Quercus alba); the MPI and FWI methods are used to reconstruct the dielectric constant distribution of the tree cross-section. Results indicate that MPI has more tolerance to the starting model, noise level and source wavelet. It can provide a more accurate image of the dielectric constant distribution compared to the conventional FWI.

scholarly journals THE INFLUENCE OF SOIL COVER ON LAKES IN NORTHERN ESTONIA

1999 ◽  
Vol 1 ◽  
pp. 220
Author(s):  
Andres Tonisson
Keyword(s):  
Soil Water ◽  
Sandy Soil ◽  
Soil Cover ◽  
Test Site ◽  
Total Emission ◽  
Soil Horizons

During the summers of 1997-98, in a pine-forested sloping watershed, soil water from calcareous and sandy soil horizons was collected on nine occasions. In total 8 lysimeters were used. The amount of water percolating through sandy test site was up to three times smaller than that through calcareous test site. The influence of soil cover on the percolating water is also significant. The sandy site is able to produce even more diluted water than that originally coming from precipitation. Concentrations of TOC are varying more than the conductivity values. The concentration of TOC on the calcareous site was 2... 2,5 times higher than that on the sandy site. The total emission of TOC from the transitional humus-rich test site could be higher by up to 20 times as compared with sandy site.

scholarly journals The Relationship of Residential Environment with The Risk of Leptospirosis in Sleman Regency

2017 ◽  
Vol 1 (2) ◽  
pp. 85-92
Author(s):  
Maya Sofiyani ◽  
M Imron Mawardi ◽  
P Sigit Purnomo ◽  
Hariza Adnani
Keyword(s):  
Environmental Factors ◽  
Case Control Study ◽  
Case Control ◽  
Survey Method ◽  
Control Programs ◽  
The Government ◽  
Relationship Of ◽  
The Relationship ◽  
Control Study ◽  
Made In

The effort of leptospirosis prevention in Sleman currently only limited to counseling and treatment of the patient, while the patient search, ways of transmission of leptospirosis from rats to humans, have never implemented in an integrated manner. The study aimed to investigated the relationship between the environmental residential condition with the risk of leptospirosis in Sleman Regency. The research used a survey method  with case control study design. The results showed that environmental factors, which are not proved to have a relationship with the risk of leptospirosis were residential condition ({p=0,108} OR=3,818 {95%CI:0,922–15,811}), the trash bin condition ({p=1,000} OR=1,138 {95%CI:0,420–3,081}) and the sewer condition ({p=0,415} OR=0,551 {95%CI:0,187–1,624}). Environmental factors that associated with the risk of leptospirosis was the presence of rats ({p=0,001} OR=13,594 {95%CI:2,754–67,107}). The effort should be made in order to prevent the increasement of Leptospirosis cases by sanitation improvement and avoiding direct contact with rats as well as it litter. The Government should be pay more attention in the vector control programs, especially in leptospirosis prone areas so the prevention effort to be able run effectively and efficiently.

Aftershocks of the Benham nuclear explosion

1969 ◽  
Vol 59 (6) ◽  
pp. 2271-2281
Author(s):  
R. M. Hamilton ◽  
J. H. Healy
Keyword(s):  
Fault Plane ◽  
Nuclear Explosion ◽  
Test Site ◽  
Strike Slip ◽  
Nevada Test Site ◽  
Ground Zero ◽  
Fault Plane Solutions ◽  
Fault Movement ◽  
Near Surface ◽  
Earthquake Distribution

abstract The Benham nuclear explosion, a 1.1 megaton test 1.4 km beneath Pahute Mesa at the Nevada Test Site, initiated a sequence of earthquakes lasting several months. The epicenters of these shocks were located within 13 km of ground zero in several linear zones that parallel the regional fault trends. Focal depths range from near surface to 6 km. The earthquakes are not located in the zone of the major ground breakage. The earthquake distribution and fault plane solutions together indicate that both right-lateral strike-slip fault movement and dip-slip fault movement occurred. The explosion apparently caused the release of natural tectonic strain.

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