2D electrical resistivity inversion and ground penetrating radar investigation of near surface cave in New Netim area, southeastern Nigeria

2021 ◽  
Author(s):  
Ebong D. Ebong ◽  
Anthony M. George ◽  
Stephen E. Ekwok ◽  
Anthony E. Akpan ◽  
Jamal Asfahani
Keyword(s):  
Electrical Resistivity ◽  
Ground Penetrating Radar ◽  
Southeastern Nigeria ◽  
Near Surface ◽  
Resistivity Inversion ◽  
Ground Penetrating

Pitfalls in near-surface geophysical interpretation: Challenging paradigms and misconceptions

2018 ◽  
Vol 6 (4) ◽  
pp. SL1-SL9 ◽  
Author(s):  
David C. Nobes ◽  
Estella Atekwana
Keyword(s):  
Electrical Resistivity ◽  
Electrical Properties ◽  
Ground Penetrating Radar ◽  
Nonaqueous Phase Liquids ◽  
Potential Fields ◽  
Near Surface ◽  
Geophysical Interpretation ◽  
Occam’S Inversion ◽  
Ground Penetrating

Too often, ideas become so well-established that they take on the roles of paradigms, and challenging those paradigms can be difficult, even if they are flawed. Similarly, misconceptions can take root and become firmly entrenched and again are difficult to dislodge. Both of these situations are fundamentally unscientific. Science makes progress when established theories are shown to be incorrect or at least incomplete. To do that, we have to let the data that we collect tell their stories. We should not impose models upon the data, but rather allow the data to yield those models that best represent those features that are absolutely necessary to fit the data, an approach often called “Occam’s inversion.” We also should not impose nonphysical and unscientific limits on our interpretation models. We evaluate several examples from our own experiences: the electrical properties of faults, nonuniqueness in potential fields, the influence of nonaqueous phase liquids and water on ground-penetrating radar and electrical resistivity, and the geophysical response of seafloor mineralization. In each case, a reviewer or another scientist questioned the conclusions using unscientific or incorrect arguments or assumptions. We must let the data speak.

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.

Ground-penetrating radar and electrical resistivity tomography studies in the biblical Pisidian Antioch city, southwest Anatolia

2018 ◽  
Vol 25 (4) ◽  
pp. 285-300 ◽  
Author(s):  
Çağlayan Balkaya ◽  
Ümit Yalçın Kalyoncuoğlu ◽  
Mehmet Özhanlı ◽  
Gözde Merter ◽  
Olcay Çakmak ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Ground Penetrating Radar ◽  
Electrical Resistivity Tomography ◽  
Resistivity Tomography ◽  
Ground Penetrating

Processing Ground Penetrating Radar Data To Improve Resolution Of Near-Surface Targets

1993 ◽  
Author(s):  
Kevin Gerlitz ◽  
Michael D. Knoll ◽  
Guy M. Cross ◽  
Robert D. Luzitano ◽  
Rosemary Knight
Keyword(s):  
Ground Penetrating Radar ◽  
Radar Data ◽  
Near Surface ◽  
Ground Penetrating
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