Vertical fracture detection by exploiting the polarization properties of ground‐penetrating radar signals

Geophysics ◽  
2004 ◽  
Vol 69 (3) ◽  
pp. 803-810 ◽  
Author(s):  
Georgios P. Tsoflias ◽  
Jean‐Paul Van Gestel ◽  
Paul L. Stoffa ◽  
Donald D. Blankenship ◽  
Mrinal Sen
Keyword(s):  
Ground Penetrating Radar ◽  
Field Measurements ◽  
Domain Modeling ◽  
Fracture Detection ◽  
Vertical Fracture ◽  
Phase Lead ◽  
Time Domain Modeling ◽  
Single Polarization ◽  
Ground Penetrating

Vertically oriented thin fractures are not always detected by conventional single‐polarization reflection profiling ground‐penetrating radar (GPR) techniques. We study the polarization properties of EM wavefields and suggest multipolarization acquisition surveying to detect the location and azimuth of vertically oriented fractures. We employ analytical solutions, 3D finite‐difference time‐domain modeling, and field measurements of multipolarization GPR data to investigate EM wave transmission through fractured geologic formations. For surface‐based multipolarization GPR measurements across vertical fractures, we observe a phase lead when the incident electric‐field component is oriented perpendicular to the plane of the fracture. This observation is consistent for nonmagnetic geologic environments and allows the determination of vertical fracture location and azimuth based on the presence of a phase difference and a phase lead relationship between varying polarization GPR data.

scholarly journals Non-Split PML Boundary Condition for Finite Element Time-Domain Modeling of Ground Penetrating Radar

2019 ◽  
Vol 07 (05) ◽  
pp. 1077-1096 ◽  
Author(s):  
Zhi Zhang ◽  
Honghua Wang ◽  
Minling Wang ◽  
Xi Guo ◽  
Guihong Guo
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Time Domain ◽  
Ground Penetrating Radar ◽  
Domain Modeling ◽  
Time Domain Modeling ◽  
Ground Penetrating

Hydrologic trajectories in transient ground-penetrating-radar reflection data

Geophysics ◽  
2010 ◽  
Vol 75 (4) ◽  
pp. WA211-WA219 ◽  
Author(s):  
Stephen M. Moysey
Keyword(s):  
Ground Penetrating Radar ◽  
Hydraulic Properties ◽  
Unsaturated Flow ◽  
Domain Modeling ◽  
Wetting Front ◽  
Computationally Efficient ◽  
Flow Models ◽  
Reflection Data ◽  
Time Domain Modeling ◽  
Ground Penetrating

A variable-rate infiltration experiment was conducted in a sandbox to demonstrate that distinctive patterns are produced in transient ground-penetrating-radar (GPR) data collected during wetting and drying events. The observed GPR response was found to be very consistent with the results of numerical simulations performed using finite-difference time-domain modeling of GPR coupled with a 1D unsaturated flow model (HYDRUS-1D) for which the sand hydraulic properties were determined independently using core samples. Despite this agreement, few methods are available that can efficiently analyze transient GPR data to make a quantitative link between observed responses and the hydraulic properties of soils. To address this problem, a computationally efficient method is proposed that is analogous to coherency analysis used in multioffset surveys. The new method isbased on the calculation of semblance along trajectories through transient GPR data. Each trajectory represents a specific GPR arrival, e.g., the ground wave and reflections from the wetting front and subsurface boundaries. The specific path of the trajectories is controlled by the hydraulic properties of the soil, just as the normal-moveout trajectories used to calculate semblance in multioffset data are controlled by wave velocity. Because the method is based on the output of 1D unsaturated flow models, it can be used for situations with complex hydrologic boundary conditions. Good agreement was found in this study between the calculated trajectories and the arrivals observed for both simulated and empirical GPR data. A sensitivity analysis performed in this study suggests that most parameters of the Mualem–van Genuchten soil model can be identified using this approach to coherency analysis of transient GPR data.

The New Swedish Cyprus Expedition 2010. Excavations at Dromolaxia Vizatzia/Hala Sultan Tekke. Preliminary results

2011 ◽  
Vol 4 ◽  
pp. 69-98 ◽  
Author(s):  
Peter M. Fischer ◽  
Patrik Klingborg ◽  
Fanny Kärfve ◽  
Fredrika Kärfve ◽  
C. Hagberg ◽  
...  
Keyword(s):  
Ground Penetrating Radar ◽  
Main Task ◽  
Phase 2 ◽  
The North ◽  
12Th Century ◽  
Area 6 ◽  
Recent Phase ◽  
The Rich ◽  
Ground Penetrating

Determination of the complete occupational sequence of the site, including investigation of pre-12th century levels which were thoroughly studied by P. Åström since the 1970s, is the main task of the planned project. During the course of the expedition (NSCE11) in spring 2010 a ground-penetrating radar survey (GPR) was carried out at Dromolaxia Vizatzia/Hala Sultan Tekke in Area 6, leading to the discovery of a large Late Cypriote complex. The compound is bordered to the north by a substantial wall, against which nine rooms (so far) could be exposed. Two occupational phases have been verified but there are indications of a third. The suggested functions of the various structures of the most recent phase are: living, working, storage and administration spaces. The rich find contexts point to the production of textiles and metal objects, and the locally produced pottery is generally of a high quality. There are also many imports, mainly from the Mycenaean sphere of culture. The locally produced vessels from Phase 2 include the “Creature krater” which is a masterpiece of a high artistic standard. Another piece of elevated artistry is the piece of a “Warrior vase”.

scholarly journals Detection of Tree Roots in an Urban Area with the Use of Ground Penetrating Radar

2016 ◽  
Vol 17 (4) ◽  
pp. 362-370 ◽  
Author(s):  
Alexander Krainyukov ◽  
Igor Lyaksa
Keyword(s):  
Urban Area ◽  
Ground Penetrating Radar ◽  
Growth Direction ◽  
Technical Condition ◽  
Tree Roots ◽  
Secondary Processing ◽  
Non Invasive ◽  
Ground Penetrating ◽  
The Given

Abstract The paper is devoted to using ground penetrating radar (GPR) for the detection of tree roots in an urban area, since GPR allow detect the hidden objects in non invasive way. It is necessary exactly to know the growth direction, thickness and depth of the roots of the tree to confidently assert about the tree root influence on the technical condition of engineering objects and structures: of the buildings, of pavements, of roadway, of engineering communications and etc. The aim of the given research was experimentally to evaluation the possibilities of detection of tree roots in an urban area with the use of GPR on frequency 400 MHz and of algorithms of secondary processing of GPR signals. Results of interpretation of radar profile and evacuation of soil around tree show the possibility of detection of the tree roots and the determination of their parameters using one or two radar concentric profiles.

scholarly journals GPR Spectra for Monitoring Asphalt Pavements

2020 ◽  
Vol 12 (11) ◽  
pp. 1749 ◽  
Author(s):  
Josep Pedret Rodés ◽  
Adriana Martínez Reguero ◽  
Vega Pérez-Gracia
Keyword(s):  
Spectral Analysis ◽  
Ground Penetrating Radar ◽  
Wave Amplitude ◽  
Structural Condition ◽  
Asphalt Pavements ◽  
Preservation Conditions ◽  
Pavement Structures ◽  
The Fourier Transform ◽  
Ground Penetrating

Ground Penetrating Radar (GPR) is a prospecting method frequently used in monitoring asphalt pavements, especially as an optimal complement to the defection test that is commonly used for determining the structural condition of the pavements. Its application is supported by studies that demonstrate the existence of a relationship between the parameters determined in GPR data (usually travel time and wave amplitude) and the preservation conditions of the structure. However, the analysis of frequencies is rarely applied in pavement assessment. Nevertheless, spectral analysis is widespread in other fields such as medicine or dynamic analysis, being one the most common analytical methods in wave processing through use of the Fourier transform. Nevertheless, spectral analysis has not been thoroughly applied and evaluated in GPR surveys, specifically in the field of pavement structures. This work is focused on analyzing the behavior of the GPR data spectra as a consequence of different problems affecting the pavement. The study focuses on the determination of areas with failures in bituminous pavement structures. Results epitomize the sensitivity of frequencies to the materials and, in some cases, to the damage.

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