Ground penetrating radar investigations at Ahichhatra: An attempt to identify buried subsurface structures

Author(s):  
S. Sravanthi ◽  
J. N. Malik ◽  
B. Vikrama
Geophysics ◽  
2021 ◽  
pp. 1-77
Author(s):  
diego domenzain ◽  
John Bradford ◽  
Jodi Mead

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.


2019 ◽  
Vol 8 (2) ◽  
pp. 35-40
Author(s):  
Ayu Safrida ◽  
Nazli Ismail ◽  
Marwan Marwan

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


2020 ◽  
Vol 12 (10) ◽  
pp. 1583 ◽  
Author(s):  
Immo Trinks ◽  
Alois Hinterleitner

Under suitable conditions, ground-penetrating radar (GPR) measurements harbour great potential for the non-invasive mapping and three-dimensional investigation of buried archaeological remains. Current GPR data visualisations almost exclusively focus on the imaging of GPR reflection amplitudes. Ideally, the resulting amplitude maps show subsurface structures of archaeological interest in plan view. However, there exist situations in which, despite the presence of buried archaeological remains, hardly any corresponding anomalies can be observed in the GPR time- or depth-slice amplitude images. Following the promising examples set by seismic attribute analysis in the field of exploration seismology, it should be possible to exploit other attributes than merely amplitude values for the enhanced imaging of subsurface structures expressed in GPR data. Coherence is the seismic attribute that is a measure for the discontinuity between adjacent traces in post-stack seismic data volumes. Seismic coherence analysis is directly transferable to common high-resolution 3D GPR data sets. We demonstrate, how under the right circumstances, trace discontinuity analysis can substantially enhance the imaging of structural information contained in GPR data. In certain cases, considerably improved data visualisations are achievable, facilitating subsequent data interpretation. We present GPR trace coherence imaging examples taken from extensive, high-resolution archaeological prospection GPR data sets.


2018 ◽  
Vol 35 ◽  
pp. 03005
Author(s):  
Ewelina Mazurkiewicz ◽  
Łukasz Ortyl ◽  
Jerzy Karczewski

The accuracy of determining the location of detectable subsurface objects is related to the accuracy of the position of georadar traces in a given profile, which in turn depends on the precise assessment of the distance covered by an antenna. During georadar measurements the distance covered by an antenna can be determined with a variety of methods. Recording traces at fixed time intervals is the simplest of them. A method which allows for more precise location of georadar traces is recording them at fixed distance intervals, which can be performed with the use of distance triggers (such as a measuring wheel or a hip chain). The search for methods eliminating these discrepancies can be based on the measurement of spatial coordinates of georadar traces conducted with the use of modern geodetic techniques for 3-D location. These techniques include above all a GNSS satellite system and electronic tachymeters. Application of the above mentioned methods increases the accuracy of space location of georadar traces. The article presents the results of georadar measurements performed with the use of geodetic techniques in the test area of Mydlniki in Krakow. A satellite receiver Leica system 1200 and a electronic tachymeter Leica 1102 TCRA were integrated with the georadar equipment. The accuracy of locating chosen subsurface structures was compared.


2021 ◽  
Vol 15 (1) ◽  
pp. 31-45
Author(s):  
Dominik Merkle ◽  
Carsten Frey ◽  
Alexander Reiterer

AbstractMobile mapping vehicles, equipped with cameras, laser scanners (in this paper referred to as light detection and ranging, LiDAR), and positioning systems are limited to acquiring surface data. However, in this paper, a method to fuse both LiDAR and 3D ground penetrating radar (GPR) data into consistent georeferenced point clouds is presented, allowing imaging both the surface and subsurface. Objects such as pipes, cables, and wall structures are made visible as point clouds by thresholding the GPR signal’s Hilbert envelope. The results are verified with existing utility maps. Varying soil conditions, clutter, and noise complicate a fully automatized approach. Topographic correction of the GPR data, by using the LiDAR data, ensures a consistent ground height. Moreover, this work shows that the LiDAR point cloud, as a reference, increases the interpretability of GPR data and allows measuring distances between above ground and subsurface structures.


2015 ◽  
Vol 18 (4) ◽  
pp. 42-50
Author(s):  
Van Thanh Nguyen ◽  
Thuan Van Nguyen ◽  
Trung Hoai Dang

Kirchhoff migration in ground penetrating radar (GPR) has been the technique of collapsing diffraction events on unmigrated records to points, thus moving reflection events to their proper locations and creating a true image of subsurface structures. Today, the scope of Kirchhoff migration has been broadened and is a tool for electromagnetic wave velocity estimation. To optimize this algorithm, we propose using the energy diagram as a criterion of looking for the correct propagation velocity. Using theoretical models, we demonstrated that the calculated velocities were the same as the root mean square ones up to the top of objects. The results verified on field data showed that improved sections could be obtained and the size as well as depth of anomalies were determined with high reliability.


2018 ◽  
Vol 35 ◽  
pp. 03004
Author(s):  
Dang Hoai Trung ◽  
Nguyen Van Giang ◽  
Nguyen Thanh Van

Migration methods play a significant role in processing ground penetrating radar data. Beside recovering the true image of subsurface structures from the prior designed velocity model and the raw GPR data, the migration algorithm could be an effective tool in bulding real environmental velocity model. In this paper, we have proposed one technique using energy diagram extracted from migrated data as a criterion of looking for the correct velocity. Split Step Fourier migration, a depth migration, is chosen for facing the challenge where the velocity varies laterally and vertically. Some results verified on field data on Vietnam show that migrated sections with calculated velocity from energy diagram have the best quality.


2017 ◽  
Vol 17 (4B) ◽  
pp. 161-166
Author(s):  
Dang Hoai Trung ◽  
Nguyen Van Giang ◽  
Nguyen Thanh Van ◽  
Nguyen Van Thuan ◽  
Vo Minh Triet

Migration methods play an essential role in processing ground penetrating radar data. For estimating electromagnetic propagation velocity distribution, the finite - difference migration is used because of its reliable performance with high noise conditions. To optimize this migration algorithm, we propose using energy diagram as a criterion of looking for the correct velocity. If the velocity varies laterally and vertically, split step Fourier migration is used for creating a true image of subsurface structures. We applied these steps to real data in Vietnam. The results verified on field data show that migrated images with calculated velocity from energy diagram have the best quality.


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