Ground‐penetrating radar: Wave theory and numerical simulation in lossy anisotropic media

1995 ◽  
Author(s):  
José M. Carcione
Keyword(s):  
Numerical Simulation ◽  
Ground Penetrating Radar ◽  
Anisotropic Media ◽  
Wave Theory ◽  
Ground Penetrating ◽  
Radar Wave

The Application of Two Dimensional Numerical Simulation Method of Ground Penetrating Radar in Concrete Dam Nondestructive Testing

2014 ◽  
Vol 1030-1032 ◽  
pp. 879-884
Author(s):  
Lan Chen ◽  
Ji Gen Liu ◽  
Yi Feng Wang ◽  
Jun Niu
Keyword(s):  
Numerical Simulation ◽  
Time Domain ◽  
Ground Penetrating Radar ◽  
Wave Theory ◽  
Simulation Method ◽  
Concrete Dam ◽  
Simulation Process ◽  
Working Principle ◽  
Ground Penetrating ◽  
Finite Different Time Domain

electromagnetic wave theory was used by ground penetrating radar, the defects in concrete dams were judged according to the measured concrete reflection waveform, frequency and wave velocity. The working principle of ground penetrating radar and numerical simulation process based on the finite different time domain method were studied, cracks, voids images in concrete was forward simulated by the above method. It was important to determine the quality defects in concrete.

Laboratory test of snow wetness influence on electrical conductivity measured with ground penetrating radar

2009 ◽  
Vol 40 (1) ◽  
pp. 33-44 ◽  
Author(s):  
Nils Granlund ◽  
Angela Lundberg ◽  
James Feiccabrino ◽  
David Gustafsson
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Laboratory Test ◽  
Liquid Water ◽  
Ground Penetrating Radar ◽  
Wave Attenuation ◽  
Radar Measurements ◽  
Ground Penetrating ◽  
Radar Wave ◽  
The Relationship

Ground penetrating radar operated from helicopters or snowmobiles is used to determine snow water equivalent (SWE) for annual snowpacks from radar wave two-way travel time. However, presence of liquid water in a snowpack is known to decrease the radar wave velocity, which for a typical snowpack with 5% (by volume) liquid water can lead to an overestimation of SWE by about 20%. It would therefore be beneficial if radar measurements could also be used to determine snow wetness. Our approach is to use radar wave attenuation in the snowpack, which depends on electrical properties of snow (permittivity and conductivity) which in turn depend on snow wetness. The relationship between radar wave attenuation and these electrical properties can be derived theoretically, while the relationship between electrical permittivity and snow wetness follows a known empirical formula, which also includes snow density. Snow wetness can therefore be determined from radar wave attenuation if the relationship between electrical conductivity and snow wetness is also known. In a laboratory test, three sets of measurements were made on initially dry 1 m thick snowpacks. Snow wetness was controlled by stepwise addition of water between radar measurements, and a linear relationship between electrical conductivity and snow wetness was established.

DNAPL mapping by ground penetrating radar examined via numerical simulation

2009 ◽  
Vol 69 (3-4) ◽  
pp. 140-149 ◽  
Author(s):  
Victoria Wilson ◽  
Christopher Power ◽  
Antonios Giannopoulos ◽  
Jason Gerhard ◽  
Gavin Grant
Keyword(s):  
Numerical Simulation ◽  
Ground Penetrating Radar ◽  
Ground Penetrating

Ground‐penetrating radar velocity tomography in heterogeneous and anisotropic media

Geophysics ◽  
1997 ◽  
Vol 62 (6) ◽  
pp. 1758-1773 ◽  
Author(s):  
Don W. Vasco ◽  
John E. Peterson ◽  
Ki Ha Lee
Keyword(s):  
Ground Penetrating Radar ◽  
Electromagnetic Waves ◽  
Numerical Technique ◽  
Anisotropic Media ◽  
Perturbation Approach ◽  
Low Velocity ◽  
Weak Anisotropy ◽  
Geological Features ◽  
Velocity Anomalies ◽  
Ground Penetrating

A ray series solution for Maxwell's equations provides an efficient numerical technique for calculating wavefronts and raypaths associated with electromagnetic waves in anisotropic media. Using this methodology and assuming weak anisotropy, we show that a perturbation of the anisotropic structure may be related linearly to a variation in the traveltime of an electromagnetic wave. Thus, it is possible to infer lateral variations in the dielectric permittivity and magnetic permeability matrices. The perturbation approach is used to analyze a series of crosswell ground‐penetrating radar surveys conducted at the Idaho National Engineering Laboratory. Several important geological features are imaged, including a rubble zone at the interface between two basalt flows. Linear low‐velocity anomalies are imaged clearly and are continuous across well pairs.

scholarly journals Railway ballast condition assessment using ground-penetrating radar – An experimental, numerical simulation and modelling development

2017 ◽  
Vol 140 ◽  
pp. 508-520 ◽  
Author(s):  
Andrea Benedetto ◽  
Fabio Tosti ◽  
Luca Bianchini Ciampoli ◽  
Alessandro Calvi ◽  
Maria Giulia Brancadoro ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Ground Penetrating Radar ◽  
Condition Assessment ◽  
Railway Ballast ◽  
Simulation And Modelling ◽  
Ground Penetrating

scholarly journals High-resolution hydrothermal structure of Hansbreen, Spitsbergen, mapped by ground-penetrating radar

1999 ◽  
Vol 45 (151) ◽  
pp. 524-532 ◽  
Author(s):  
J.C. Moore ◽  
A. Pälli ◽  
F. Ludwig ◽  
H. Blatter ◽  
J. Jania ◽  
...  
Keyword(s):  
High Resolution ◽  
Ground Penetrating Radar ◽  
Water Levels ◽  
Large Water ◽  
Complex Temperature ◽  
Polythermal Glacier ◽  
Ground Penetrating ◽  
Isolated Point ◽  
Radar Wave ◽  
Water Contents

AbstractDetailed ground-penetrating radar (GPR) surveys at 50 and 200 MHz on Hansbreen, a polythermal glacier in southern Svalbard, are presented and interpreted. Comparison of the variations in character of the radar reflections with borehole thermometry and water levels in moulins suggests that GPR can be used to study the hydrothermal properties of the glacier. The high resolution of the GPR data shows that the hydrothermal structure of the glacier is highly variable both along the centre line and on transverse profiles. Water contents for many places and depths within the glacier were calculated by estimating radar-wave velocities to point reflectors. We find typical water contents of 1-2% for the temperate ice, but wetter ice associated with surface crevassing and moulins (typically 4% water content). There is evidence that wet ice sometimes overlays drier ice. The hydrothermal structure is thus shown to be very complex. Temperature gradients in the cold ice indicate freezing rates of temperate ice below cold ice of 0.1-0.5 ma-1, while isolated point reflectors within the cold ice indicate large water-filled bodies that are probably related to the regular drainage structure of the glacier.

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