DETECTION OF ROAD CAVITIES IN URBAN CITIES BY 3D GROUND PENETRATING RADAR

Geophysics ◽  
2021 ◽  
pp. 1-44
Author(s):  
Hai Liu ◽  
Zhenshi Shi ◽  
Jianhui Li ◽  
Chao Liu ◽  
Xu Meng ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Antenna Arrays ◽  
Ground Penetrating Radar ◽  
Data Interpretation ◽  
Cavity Depth ◽  
Near Surface ◽  
Horizontal Size ◽  
3D Gpr ◽  
One Year ◽  
Ground Penetrating

Cavities under urban roads have increasingly become a great threat to the traffic safety in many cities. As a quick, effective, and high-resolution geophysical method, ground penetrating radar (GPR) has been widely used to detect and image near-surface objects. However, the interpretation of field GPR data is still challenging. For example, it is hard to distinguish reflections caused by road cavities or other urban utilities by a conventional 2D GPR survey. The superiority of 3D GPR in data interpretation is demonstrated by a laboratory experiment. Two pipes and a glass-made cavity buried in a sandpit show similar hyperbolic reflections in the 2D GPR profiles, and are hard to be discriminated. In contrast, their geometric shapes and dimensions are readily identified in the 3D image reconstructed from the synthetic 3D GPR dataset. Thus, a car-mounted 3D GPR system with two antenna arrays oriented in different polarization directions is developed, and has detected over 100 cavities in three Chinese cities over the past one year. The field data of two of the cavities are presented. As a result, the cavity depth, horizontal size and height can be accurately estimated from the 3D GPR dataset. Both laboratory and field experimental results indicate that 3D GPR possesses a great potential in detection and recognition of road cavities and utilities in the complicated urban environment.

scholarly journals Ground-penetrating radar signature of Quaternary faulting: a study from the Mt. Pollino region, southern Apennines, Italy

Solid Earth ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 2573-2596
Author(s):  
Maurizio Ercoli ◽  
Daniele Cirillo ◽  
Cristina Pauselli ◽  
Harry M. Jol ◽  
Francesco Brozzetti
Keyword(s):  
Ground Penetrating Radar ◽  
Late Quaternary ◽  
Normal Fault ◽  
Data Interpretation ◽  
Seismic Gap ◽  
Southern Apennines ◽  
Near Surface ◽  
3D Gpr ◽  
2D Data ◽  
Ground Penetrating

Abstract. With the aim of unveiling evidence of Late Quaternary faulting, a series of ground-penetrating radar (GPR) profiles were acquired across the southern portion of the Fosso della Valle–Campotenese normal fault (VCT), located at the Campotenese continental basin (Mt. Pollino region) in the southern Apennines active extensional belt (Italy). A set of 49 GPR profiles, traced nearly perpendicular to this normal fault, was acquired using 300 and 500 MHz antennas and carefully processed through a customized workflow. The data interpretation allowed us to reconstruct a pseudo-3D model depicting the boundary between the Mesozoic bedrock and the sedimentary fill of the basin, which were in close proximity to the fault. Once the GPR signature of faulting was reviewed and defined, we interpret near-surface alluvial and colluvial sediments dislocated by a set of conjugate (W- and E-dipping) discontinuities that penetrate inside the underlying Triassic dolostones. Close to the contact between the continental deposits and the bedrock, some buried scarps which offset wedge-shaped deposits are interpreted as coseismic ruptures, subsequently sealed by later deposits. Our pseudo-3D GPR dataset represented a good trade-off between a dense 3D-GPR volume and conventional 2D data, which normally requires a higher degree of subjectivity during the interpretation. We have thus reconstructed a reliable subsurface fault pattern, discriminating master faults and a series of secondary splays. This contribution better characterizes active Quaternary faults in an area which falls within the Pollino seismic gap and is considered prone to severe surface faulting. Our results encourage further research at the study site, whilst we also recommend our workflow for similar regions characterized by high seismic hazard and scarcity of near-surface geophysical data.

scholarly journals 3D GPR Image-based UcNet for Enhancing Underground Cavity Detectability

2019 ◽  
Vol 11 (21) ◽  
pp. 2545 ◽  
Author(s):  
Man-Sung Kang ◽  
Namgyu Kim ◽  
Seok Been Im ◽  
Jong-Jae Lee ◽  
Yun-Kyu An
Keyword(s):  
Ground Penetrating Radar ◽  
Super Resolution ◽  
Data Interpretation ◽  
Dependent Data ◽  
Test Results ◽  
Underground Cavity ◽  
Cavity Detection ◽  
3D Gpr ◽  
Ground Penetrating

This paper proposes a 3D ground penetrating radar (GPR) image-based underground cavity detection network (UcNet) for preventing sinkholes in complex urban roads. UcNet is developed based on convolutional neural network (CNN) incorporated with phase analysis of super-resolution (SR) GPR images. CNNs have been popularly used for automated GPR data classification, because expert-dependent data interpretation of massive GPR data obtained from urban roads is typically cumbersome and time consuming. However, the conventional CNNs often provide misclassification results due to similar GPR features automatically extracted from arbitrary underground objects such as cavities, manholes, gravels, subsoil backgrounds and so on. In particular, non-cavity features are often misclassified as real cavities, which degrades the CNNs’ performance and reliability. UcNet improves underground cavity detectability by generating SR GPR images of the cavities extracted from CNN and analyzing their phase information. The proposed UcNet is experimentally validated using in-situ GPR data collected from complex urban roads in Seoul, South Korea. The validation test results reveal that the underground cavity misclassification is remarkably decreased compared to the conventional CNN ones.

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.

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

scholarly journals Investigating the Performance of Bi-Static GPR Antennas for Near-Surface Object Detection

Sensors ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 170 ◽  
Author(s):  
Xianyang Gao ◽  
Frank J. W. Podd ◽  
Wouter Van Verre ◽  
David J. Daniels ◽  
Anthony J. Peyton
Keyword(s):  
Ground Penetrating Radar ◽  
Input Impedance ◽  
Test Site ◽  
Late Time ◽  
Near Surface ◽  
Object Depth ◽  
Ground Penetrating ◽  
Antenna Input ◽  
Surface Object ◽  
Bow Tie

Antennas are an important component in ground penetrating radar (GPR) systems. Although there has been much research reported on the design of individual antennas, there is less research reported on the design of the geometry of bi-static antennas. This paper considers the effects of key parameters in the setup of a GPR head consisting of a bi-static bow-tie pair to show the effect of these parameters on the GPR performance. The parameters investigated are the antenna separation, antenna height above the soil, and antenna input impedance. The investigation of the parameters was performed by simulation and measurements. It was found when the bi-static antennas were separated by 7 cm to 9 cm and were operated close to the soil (2 cm to 4 cm), the reflected signal from a near-surface object is relatively unaffected by height variation and object depth. An antenna input impedance of 250 Ω was chosen to feed the antennas to reduce the late-time ringing. Using these results, a new GPR system was designed and then evaluated at a test site near Benkovac, Croatia.

Advances in Near-Surface Seismology and Ground-Penetrating Radar

2013 ◽  
Vol 12 (1) ◽  
pp. vzj2012.0026br
Author(s):  
Gregory S. Baker
Keyword(s):  
Ground Penetrating Radar ◽  
Near Surface ◽  
Ground Penetrating

scholarly journals A Microwave Tomography Strategy for Underwater Imaging via Ground Penetrating Radar

2018 ◽  
Vol 10 (9) ◽  
pp. 1410 ◽  
Author(s):  
Giovanni Ludeno ◽  
Luigi Capozzoli ◽  
Enzo Rizzo ◽  
Francesco Soldovieri ◽  
Ilaria Catapano
Keyword(s):  
Ground Penetrating Radar ◽  
Homogeneous Medium ◽  
Diagnostic Techniques ◽  
Reference Scenario ◽  
Underwater Imaging ◽  
The Family ◽  
Horizontal Size ◽  
Imaging Strategy ◽  
Ground Penetrating ◽  
Underwater Structures

Detection and monitoring of underwater structures is one of the most challenging applicative scenarios for remote sensing diagnostic techniques, among which ground penetrating radar (GPR). With this aim, an imaging strategy belonging to the family of microwave tomographic approaches is proposed herein. This strategy allows the imaging of objects located into a wet sand medium below a freshwater layer and it can find application in investigation of lakes, rivers, and hydraulic structures. The proposed strategy accounts for the layered structure of the scenario under test by exploiting a spatially variable equivalent permittivity in the inverse scattering model. This allows a reliable reconstruction of depth and horizontal size of underwater hidden objects. The imaging capabilities of the strategy are verified by processing experimental data referred to a laboratory environment reproducing a submerged archeological site at scale 1:1. The results are compared with those obtained by modelling the reference scenario as a homogeneous medium, in order to verify the effective improvement in terms of reconstruction accuracy.

Sign in / Sign up

Export Citation Format

Share Document