Time-domain inversion of GPR data containing attenuation due to conductive losses

Geophysics ◽  
2006 ◽  
Vol 71 (5) ◽  
pp. K103-K109 ◽  
Author(s):  
Qingyun Di ◽  
Meigen Zhang ◽  
Maioyue Wang
Keyword(s):  
Time Domain ◽  
Ground Penetrating Radar ◽  
Seismic Data ◽  
Random Noise ◽  
Synthetic Data ◽  
The Time Domain ◽  
Ground Penetrating ◽  
Domain Inversion ◽  
Inversion Techniques ◽  
And Inversion

Many seismic data processing and inversion techniques have been applied to ground-penetrating radar (GPR) data without including the wave field attenuation caused by conductive ground. Neglecting this attenuation often reduces inversion resolution. This paper introduces a GPR inversion technique that accounts for the effects of attenuation. The inversion is formulated in the time domain with the synthetic GPR waveforms calculated by a finite-element method (FEM). The Jacobian matrix can be computed efficiently with the same FEM forward modeling procedure. Synthetic data tests show that the inversion can generate high-resolution subsurface velocity profiles even with data containing strong random noise. The inversion can resolve small objects not readily visible in the waveforms. Further, the inversion yields a dielectric constant that can help to determine the types of material filling underground cavities.

Depth-domain seismic reflectivity inversion with compressed sensing technique

2017 ◽  
Vol 5 (1) ◽  
pp. T1-T9 ◽  
Author(s):  
Rui Zhang ◽  
Kui Zhang ◽  
Jude E. Alekhue
Keyword(s):  
Compressed Sensing ◽  
Time Domain ◽  
Seismic Data ◽  
Reservoir Characterization ◽  
Synthetic Data ◽  
Seismic Inversion ◽  
Inversion Method ◽  
Depth Migration ◽  
Band Limited ◽  
The Time Domain

More and more seismic surveys produce 3D seismic images in the depth domain by using prestack depth migration methods, which can present a direct subsurface structure in the depth domain rather than in the time domain. This leads to the increasing need for applications of seismic inversion on the depth-imaged seismic data for reservoir characterization. To address this issue, we have developed a depth-domain seismic inversion method by using the compressed sensing technique with output of reflectivity and band-limited impedance without conversion to the time domain. The formulations of the seismic inversion in the depth domain are similar to time-domain methods, but they implement all the elements in depth domain, for example, a depth-domain seismic well tie. The developed method was first tested on synthetic data, showing great improvement of the resolution on inverted reflectivity. We later applied the method on a depth-migrated field data with well-log data validated, showing a great fit between them and also improved resolution on the inversion results, which demonstrates the feasibility and reliability of the proposed method on depth-domain seismic data.

scholarly journals ESTIMATING DIELECTRIC PERMITTIVITY AND ELECTRIC CONDUCTIVITY FROM SIMULATED MULTICHANNEL GPR PULSES USING ACO AND QUASI-NEWTON INVERSION TECHNIQUES

2014 ◽  
Vol 32 (4) ◽  
pp. 595
Author(s):  
Maria Da Graça Gomes ◽  
Roberto Pinto Souto ◽  
Alexandre Sacco de Athayde ◽  
Marco Túllio Menna Barreto de Vilhena ◽  
Adelir José Strieder
Keyword(s):  
Dielectric Permittivity ◽  
Electric Conductivity ◽  
Ground Penetrating Radar ◽  
Random Noise ◽  
Radar Data ◽  
Inversion Algorithm ◽  
Algorithm Performance ◽  
Ground Penetrating ◽  
Inversion Techniques ◽  
Quasi Newton

ABSTRACT. Inversion of synthetic ground-penetrating radar data to estimate both dielectric permittivity (ε) and electric conductivity (σ) properties simultaneouslyis presented in this paper. The synthetic Ground-Penetrating Radar (GPR) data was generated by the propagation of a one-dimensional electromagnetic wave (1-D EMwave) through a given geological model. The simulated EM trace was modeled by Finite Difference Time Domain method (FDTD) for three different frequencies (f):800, 1000 and 1200 MHz. Random noise was also introduced to evaluate inversion algorithm performance. The inversion of GPR data was performed by Ant ColonyOptimization (ACO) and Quasi-Newton (QN) techniques. A modified ACO technique was applied to approximate conductivity for deepest positions, and to increase theaccuracy and convergence along lower positions. The inversion techniques were able to estimate simultaneously the dielectric permittivity and electric conductivity fromsynthetic multi-frequency GPR data. The estimated electrical parameters can be used to derive a set of physical properties and to develop a better understanding of theunderground geological or geotechnical media.Keywords: ground-penetrating radar, inversion of GPR data, Ant Colony Optimization, Quasi-Newton technique. RESUMO. Neste artigo apresenta-se o registro das ondas eletromagnéticas refletidas (dados sintéticos) e o uso deste registro em algoritmos de inversão que procuramestimar simultaneamente as propriedades permissividade elétrica (ε) e condutividade elétrica (σ). Os dados GPR sintéticos foram gerados pela propagação da onda unidimensional através de um determinado modelo geológico. O traço da onda eletromagnética (OEM) simulado foi modelado pelo método das diferenças finitasno domínio do tempo (FDTD) para três diferentes frequências (f): 800, 1000 e 1200 MHz. Os ruídos randômicos foram introduzidos para verificar a performance doalgoritmo de inversão. Os dados de inversão GPR (permissividade dielétrica e condutividade elétrica) foram obtidos pelos métodosAnt Colony Optimization (Otimização da Colônia de Formigas) (ACO) e Quasi-Newton (QN). O método ACO modificado foi aplicado para aproximar a condutividade em posições mais profundas e aumentara precisão e a convergência ao longo da profundidade. Os métodos de inversão foram capazes de estimar simultaneamente duas propriedades do modelo geológico:a permissividade elétrica e a condutividade elétrica para levantamentos georradar multicanais. Os parâmetros elétricos estimados podem ser usados para derivar umconjunto de propriedades físicas e melhorar a compreensão dos meios geológico-geotécnicos em subsolo.Palavras-chave: radar de penetração no solo, inversão de dados GPR, Otimização da Colônia de Formigas, método Quasi-Newton.

scholarly journals Comparison of modelled and observed responses of a glacier snowpack to ground-penetrating radar

2003 ◽  
Vol 37 ◽  
pp. 293-297 ◽  
Author(s):  
Jack Kohler ◽  
John C. Moore ◽  
Elisabeth Isaksson
Keyword(s):  
High Resolution ◽  
Time Domain ◽  
Ground Penetrating Radar ◽  
Ice Core ◽  
Reflection Coefficients ◽  
Order Of Magnitude ◽  
The Time Domain ◽  
Ground Penetrating ◽  
Physical And Chemical ◽  
Firn Core

AbstractThe upper 10 m of the firn of a Svalbard glacier is imaged along the centre line using a 500 MHz ground-penetrating radar, and a 10 m firn core taken along the profile. Complex reflection coefficients are calculated from the high-resolution capacitance and conductance measurements made on the snow core. The reflection coefficient depth series is converted to the time domain and convolved with model radar monopulses to synthesize traces that compare well with radar traces recorded near the ice core. Differences are probably due to cm-scale physical and chemical inhomogeneities that are smoothed when imaged by the radar beam, which integrates information over areas that are of the same order of magnitude as the depth to the layer.

Application of complex-trace analysis to seismic data for random-noise suppression and temporal resolution improvement

Geophysics ◽  
2006 ◽  
Vol 71 (3) ◽  
pp. V79-V86 ◽  
Author(s):  
Hakan Karsli ◽  
Derman Dondurur ◽  
Günay Çifçi
Keyword(s):  
Seismic Data ◽  
Trace Analysis ◽  
Noise Suppression ◽  
Single Channel ◽  
Random Noise ◽  
Synthetic Data ◽  
Low Frequency ◽  
Bright Spot ◽  
Phase Information ◽  
Resolution Improvement

Time-dependent amplitude and phase information of stacked seismic data are processed independently using complex trace analysis in order to facilitate interpretation by improving resolution and decreasing random noise. We represent seismic traces using their envelopes and instantaneous phases obtained by the Hilbert transform. The proposed method reduces the amplitudes of the low-frequency components of the envelope, while preserving the phase information. Several tests are performed in order to investigate the behavior of the present method for resolution improvement and noise suppression. Applications on both 1D and 2D synthetic data show that the method is capable of reducing the amplitudes and temporal widths of the side lobes of the input wavelets, and hence, the spectral bandwidth of the input seismic data is enhanced, resulting in an improvement in the signal-to-noise ratio. The bright-spot anomalies observed on the stacked sections become clearer because the output seismic traces have a simplified appearance allowing an easier data interpretation. We recommend applying this simple signal processing for signal enhancement prior to interpretation, especially for single channel and low-fold seismic data.

Successful Application of Ground-Penetrating Radar for Quality Assurance-Quality Control of New Pavements

2003 ◽  
Vol 1861 (1) ◽  
pp. 86-97 ◽  
Author(s):  
Imad L. Al-Qadi ◽  
Samer Lahouar ◽  
Amara Loulizi
Keyword(s):  
Quality Control ◽  
Quality Assurance ◽  
Ground Penetrating Radar ◽  
Test Section ◽  
Base Layer ◽  
Quality Control Tool ◽  
Granular Base ◽  
The One ◽  
The Time Domain ◽  
Ground Penetrating

The successful application of ground-penetrating radar (GPR) as a quality assurance–quality control tool to measure the layer thicknesses of newly built pavement systems is described. A study was conducted on a newly built test section of Route 288 located near Richmond, Virginia. The test section is a three-lane, 370-m-long flexible pavement system composed of a granular base layer and three different hot-mix asphalt (HMA) lifts. GPR surveys were conducted on each lift of the HMA layers after they were constructed. To estimate the layer thicknesses, GPR data were analyzed by using simplified equations in the time domain. The accuracies of the GPR system results were checked by comparing the thicknesses predicted with the GPR to the thicknesses measured directly from a large number of cores taken from the different HMA lifts. This comparison revealed a mean thickness error of 2.9% for HMA layers ranging in thickness from 100 mm (4 in.) to 250 mm (10 in.). This error is similar to the one obtained from the direct measurement of core thickness.

scholarly journals Advanced Inversion Techniques for Ground Penetrating Radar

2017 ◽  
pp. 37-42 ◽  
Author(s):  
Alessandro Fedeli ◽  
Matteo Pastorino ◽  
Andrea Randazzo
Keyword(s):  
Cultural Heritage ◽  
Ground Penetrating Radar ◽  
Civil Engineering ◽  
Needed Information ◽  
Ground Penetrating ◽  
Inversion Techniques

Ground Penetrating Radar (GPR) systems arenowadays standard inspection tools in several application areas, such as subsurface prospecting, civil engineering and cultural heritage monitoring. Usually, the raw output of GPR isprovided as a B-scan, which has to be further processed inorder to extract the needed information about the inspectedscene. In this framework, inversescattering-based approachesare gaining an ever-increasing interest, thanks to their capabil-ities of directly providing images of the physical and dielectricproperties of the investigated areas. In this paper, some advances in the development of such inversion techniques in theGPR field are revised and discussed.

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