scholarly journals Sensitivity Analysis for Joint Inversion of Ground-Penetrating Radar and Thermal-Hydrological Data from a Large-Scale Underground Heater Test

2008 ◽  
Vol 164 (2) ◽  
pp. 169-179 ◽  
Author(s):  
M. B. Kowalsky ◽  
J. Birkholzer ◽  
J. Peterson ◽  
S. Finsterle ◽  
S. Mukhopadhyay ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Ground Penetrating Radar ◽  
Large Scale ◽  
Joint Inversion ◽  
Hydrological Data ◽  
Ground Penetrating

Joint full-waveform GPR and ER inversion applied to field data acquired on the surface

Geophysics ◽  
2021 ◽  
pp. 1-77
Author(s):  
diego domenzain ◽  
John Bradford ◽  
Jodi Mead
Keyword(s):  
Ground Penetrating Radar ◽  
Joint Inversion ◽  
Waveform Inversion ◽  
Shallow Groundwater ◽  
Computational Domain ◽  
Alluvial Deposits ◽  
Subsurface Structures ◽  
Full Waveform ◽  
Stable Source ◽  
Ground Penetrating

We exploit the different but complementary data sensitivities of ground penetrating radar (GPR) and electrical resistivity (ER) by applying a multi-physics, multi-parameter, simultaneous 2.5D joint inversion without invoking petrophysical relationships. Our method joins full-waveform inversion (FWI) GPR with adjoint derived ER sensitivities on the same computational domain. We incorporate a stable source estimation routine into the FWI-GPR.We apply our method in a controlled alluvial aquifer using only surface acquired data. The site exhibits a shallow groundwater boundary and unconsolidated heterogeneous alluvial deposits. We compare our recovered parameters to individual FWI-GPR and ER results, and to log measurements of capacitive conductivity and neutron-derived porosity. Our joint inversion provides a more representative depiction of subsurface structures because it incorporates multiple intrinsic parameters, and it is therefore superior to an interpretation based on log data, FWI-GPR, or ER alone.

Model Track Studies by Ground Penetrating Radar (GPR) on Ballast With Different Fouling and Geotechnical Properties

2015 ◽  
Author(s):  
Hamed Faghihi Kashani ◽  
Carlton L. Ho ◽  
Charles P. Oden ◽  
Stanley S. Smith
Keyword(s):  
Ground Penetrating Radar ◽  
Large Scale ◽  
Empirical Studies ◽  
Geotechnical Properties ◽  
Maintenance Cost ◽  
Non Invasive ◽  
Section Area ◽  
University Of Massachusetts ◽  
Ground Penetrating ◽  
The University

In recent years there has been an increase in the knowledge of, and need for, non-invasive monitoring of ballast in order to identify the problematic sections of track and decrease the maintenance cost. Various technologies such as Ground Penetrating Radar (GPR) are becoming accepted for investigating the condition of ballast. However since these techniques were not originally developed for engineering applications, their applicability in ballast evaluations can be sometimes uncertain. Continued empirical studies and condition specific calibrations are needed to demonstrate repeatable and quantifiable results. In this study large-scale track models with trapezoidal section area were constructed at the University of Massachusetts to investigate the effects of breakdown fouling, and the effects of changing geotechnical properties on GPR traces. This paper presents the design and construction of large scale track models, and methods used for GPR data collection. GPR data are presented in this paper that demonstrate sensitivity to the track model properties and variables. In particular, the experiments are being used to evaluate changes in GPR data with changing geotechnical properties of the ballast such as density, water content, grain size distribution (GSD), and fouling percentage.

Joint inversion of full-waveform ground-penetrating radar and electrical resistivity data: Part 1

Geophysics ◽  
2020 ◽  
Vol 85 (6) ◽  
pp. H97-H113 ◽  
Author(s):  
Diego Domenzain ◽  
John Bradford ◽  
Jodi Mead
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Ground Penetrating Radar ◽  
Joint Inversion ◽  
Geophysical Methods ◽  
Data Types ◽  
Full Waveform ◽  
Electrical Permittivity ◽  
Ground Penetrating ◽  
Subsurface Geometry

We have developed an algorithm for joint inversion of full-waveform ground-penetrating radar (GPR) and electrical resistivity (ER) data. The GPR data are sensitive to electrical permittivity through reflectivity and velocity, and electrical conductivity through reflectivity and attenuation. The ER data are directly sensitive to the electrical conductivity. The two types of data are inherently linked through Maxwell’s equations, and we jointly invert them. Our results show that the two types of data work cooperatively to effectively regularize each other while honoring the physics of the geophysical methods. We first compute sensitivity updates separately for the GPR and ER data using the adjoint method, and then we sum these updates to account for both types of sensitivities. The sensitivities are added with the paradigm of letting both data types always contribute to our inversion in proportion to how well their respective objective functions are being resolved in each iteration. Our algorithm makes no assumptions of the subsurface geometry nor the structural similarities between the parameters with the caveat of needing a good initial model. We find that our joint inversion outperforms the GPR and ER separate inversions, and we determine that GPR effectively supports ER in regions of low conductivity, whereas ER supports GPR in regions with strong attenuation.

Ground-penetrating radar and coring used to study the large-scale structure of point-bar deposits in three dimensions

Sedimentology ◽  
1995 ◽  
Vol 42 (6) ◽  
pp. 839-852 ◽  
Author(s):  
JOHN S. BRIDGE ◽  
JAN ALEXANDER ◽  
RICHARD E. LL. COLLIER ◽  
ROB. L. GAWTHORPE ◽  
JACK JARVIS
Keyword(s):  
Ground Penetrating Radar ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Three Dimensions ◽  
Point Bar ◽  
Ground Penetrating

scholarly journals Frequency components of radargrams in analyses of shallow soil cavities

2018 ◽  
Vol 7 (2.13) ◽  
pp. 127
Author(s):  
Daniliev S.M ◽  
Danilieva N.A
Keyword(s):  
Electromagnetic Wave ◽  
Ground Penetrating Radar ◽  
Large Scale ◽  
Experimental Studies ◽  
Technical Condition ◽  
Filling Material ◽  
Field Frequency ◽  
Inverse Fourier Transformation ◽  
Industrial Buildings ◽  
Ground Penetrating

The urgency of the issue being studied is determined by widespread large-scale implementation of ground penetrating radar (GPR) method within the study practice of technical state of various engineering-geological sites over a long operational period. Such buildings and structures as dams, architectural landmarks, residential and industrial buildings, temples and churches, roadways and takeoff runways may be referred to main engineering and geological sites which have been studied via ground penetrating radar method. Cracks of different length, orientation and opening, as well as cavities of various localization, being distinguished by filling material, are the main types of irregularities in the above-mentioned sites, which were being formed in the process of prolonged or improper operation. However, due to vastness of the irregularities being studied and the impossibility to include all the types of possible defects into this article, we have settled on the cavities which are the most commonly encountered in the course of practice only. This article considers the approach to analysis of the electromagnetic wave field frequency characteristics being applied during conducting ground penetrating radar studies of irregularities in the structure of engineering-geological sites on the basis of the results of electromagnetic wave fields mathematical simulation, and of the results obtained in experimental studies at real engineering-geological sites as well. There has been proposed a method based of inverse Fourier transformation for studying spectrum shift in georadargrams. The georadargram is a set of registered signals, which is obtained during even movement of the georadar along the survey line. Due to that, this article is aimed at attraction of analysis of wave electromagnetic field attributes in addition to standard methods of ground penetrating radar (GPR) data processing and interpretation, which allows to extend significantly prospect capabilities of GPR method by obtaining extra data on heterogeneous zones parameters at engineering and geological sites, and, thus, proceed from qualitative notions on technical condition of studied object to quantitative ones.  

scholarly journals Investigation of Shallow Fault Structures Using Ground Penetrating Radar Method in Gampong Pangwa Trienggadeng District, Pidie Jaya Regency

2019 ◽  
Vol 8 (2) ◽  
pp. 35-40
Author(s):  
Ayu Safrida ◽  
Nazli Ismail ◽  
Marwan Marwan
Keyword(s):  
Ground Penetrating Radar ◽  
Large Scale ◽  
Ground Movement ◽  
Subsurface Structure ◽  
Profile Data ◽  
The Road ◽  
Subsurface Structures ◽  
Fault Structures ◽  
Fault Trace ◽  
Ground Penetrating

Wilayah Aceh merupakan wilayah yang sering terjadi gempa bumi dengan skala besar. Salah satu gempa bumi dengan skala besar adalah Gempa Pidie Jaya yang terjadi pada 7 Desember 2016. Setelah terjadi gempa bumi, banyak terjadi pergerakan tanah yang ditemukan di area penelitian. Telah dilakukan serangkaian pengukuran menggunakan Ground Penetrating Radar (80 MHz) untuk mempelajari struktur bawah permukaan setelah terjadinya gempa bumi. Penelitian ini dilakukan di Desa Pangwa, Kecamatan Trienggadeng, Kabupaten Pidie Jaya. Pengukuran dilakukan di sepanjang jalan di Desa Pangwa yang melintasi dua jembatan. Pengukuran dilakukan pada 18 lintasan dengan panjang masing–masing lintasan sepanjang 50 m. Pengolahan data dilakukan dengan menggunakan software GRED. Berdasarkan hasil radargram, kita menemukan struktur pemukaan dangkal berupa patahan di tengah gambaran radargram pada lintasan 13 yang disebabkan oleh terjadinya gempa di Pidie Jaya. The Aceh region is an area of frequent large-scale earthquakes. One of the earthquakes with a large scale is Pidie Jaya Earthquake that occurred on December 7, 2016. After the earthquake, many ground movement evidences were found in the area. The ground penetrating radar (80 MHz) measurement is used to study subsurface structures after the earthquake. This research was conducted in Pangwa Village, Trienggadeng Subdistrict, Pidie Jaya District. Measurements were carried out along the road in Pangwa Village which crossed two bridges. Data measurements were made along 18 profiles with 50 m length of each profile. Data processing were done by using GRED software. Based on processed radargrams, we found a fault trace at the middle of the profile lane 13 caused by the newest earthquake in Pidie Jaya. Keywords: Ground Penetrating Radar, Subsurface structure, electromagnetic wave velocity

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