scholarly journals Accounting for Surface Roughness Scattering in the Characterization of Forest Litter with Ground-Penetrating Radar

2019 ◽  
Vol 11 (7) ◽  
pp. 828
Author(s):  
Frédéric André ◽  
François Jonard ◽  
Mathieu Jonard ◽  
Harry Vereecken ◽  
Sébastien Lambot
Keyword(s):  
Surface Roughness ◽  
Ground Penetrating Radar ◽  
Land Surface ◽  
Forest Litter ◽  
Relative Dielectric Permittivity ◽  
In Situ Experiment ◽  
In Situ Experiments ◽  
Ground Penetrating

Accurate characterization of forest litter is of high interest for land surface modeling and for interpreting remote sensing observations over forested areas. Due to the large spatial heterogeneity of forest litter, scattering from litter layers has to be considered when sensed using microwave techniques. Here, we apply a full-waveform radar model combined with a surface roughness model to ultrawideband ground-penetrating radar (GPR) data acquired above forest litter during controlled and in situ experiments. For both experiments, the proposed modeling approach successfully described the radar data, with improvements compared to a previous study in which roughness was not directly accounted for. Inversion of the GPR data also provided reliable estimates of the relative dielectric permittivity of the recently fallen litter (OL layer) and of the fragmented litter in partial decomposition (OF layer) with, respectively, averaged values of 1.35 and 3.8 for the controlled experiment and of 3.9 and 7.5 for the in situ experiment. These results show the promising potentialities of GPR for efficient and non-invasive characterization of forest organic layers.

scholarly journals Combination of ground penetrating radar and seismic surveys of the tailings dam

2021 ◽  
Vol 938 (1) ◽  
pp. 012020
Author(s):  
A Kalashnik ◽  
A Dyakov
Keyword(s):  
Internal Structure ◽  
Ground Penetrating Radar ◽  
Water Saturation ◽  
The Body ◽  
Tailings Dam ◽  
Geophysical Surveys ◽  
In Situ Experiments ◽  
Water Saturated ◽  
Ground Penetrating

Abstract Identification of water-saturated zones in the tailings dams is an actual scientific and practical task in terms of providing, first of all, their mechanical strength and filtration stability. Use of active sounding geophysical study methods allows obtaining sufficiently detailed information about the peculiarities of the internal structure of the tailings dam and the degree of water saturation of the composing soils. The paper presents the results of in-situ experiments on the study of the tailings dam of the mining enterprise by ground penetrating radar (GPR) and seismic methods. A comparative analysis of the conducted studies has allowed clarifying the internal structure and assessing the dam’s condition, paying special attention to the identification of local zones of increased water saturation and filtration. Based on the calculated correlation coefficient of electromagnetic and seismic wave velocity values, it was revealed that synchronization of geophysical surveys allows significantly increasing the reliability of in-situ determinations, as well as obtaining more reliable data. The results of the studies are the basis for predicting the most vulnerable places (zones) of a bulk ground hydraulic facility, as well as the localization of water-saturated areas in the body of the ground structures with greater reliability and performance.

scholarly journals Characterization of tillage effects on the spatial variation of soil properties using ground-penetrating radar and electromagnetic induction

Geoderma ◽  
2013 ◽  
Vol 207-208 ◽  
pp. 310-322 ◽  
Author(s):  
François Jonard ◽  
Mohammad Mahmoudzadeh ◽  
Christian Roisin ◽  
Lutz Weihermüller ◽  
Frédéric André ◽  
...  
Keyword(s):  
Soil Properties ◽  
Spatial Variation ◽  
Ground Penetrating Radar ◽  
Electromagnetic Induction ◽  
Ground Penetrating

scholarly journals Identifying Spatial and Temporal Variations in Concrete Bridges with Ground Penetrating Radar Attributes

2021 ◽  
Vol 13 (9) ◽  
pp. 1846
Author(s):  
Vivek Kumar ◽  
Isabel M. Morris ◽  
Santiago A. Lopez ◽  
Branko Glisic
Keyword(s):  
Compressive Strength ◽  
Ground Penetrating Radar ◽  
Material Properties ◽  
Temporal Variations ◽  
Concrete Bridges ◽  
Spatial And Temporal Variation ◽  
Reflected Waves ◽  
Ground Penetrating ◽  
Over Time

Estimating variations in material properties over space and time is essential for the purposes of structural health monitoring (SHM), mandated inspection, and insurance of civil infrastructure. Properties such as compressive strength evolve over time and are reflective of the overall condition of the aging infrastructure. Concrete structures pose an additional challenge due to the inherent spatial variability of material properties over large length scales. In recent years, nondestructive approaches such as rebound hammer and ultrasonic velocity have been used to determine the in situ material properties of concrete with a focus on the compressive strength. However, these methods require personnel expertise, careful data collection, and high investment. This paper presents a novel approach using ground penetrating radar (GPR) to estimate the variability of in situ material properties over time and space for assessment of concrete bridges. The results show that attributes (or features) of the GPR data such as raw average amplitudes can be used to identify differences in compressive strength across the deck of a concrete bridge. Attributes such as instantaneous amplitudes and intensity of reflected waves are useful in predicting the material properties such as compressive strength, porosity, and density. For compressive strength, one alternative approach of the Maturity Index (MI) was used to estimate the present values and compare with GPR estimated values. The results show that GPR attributes could be successfully used for identifying spatial and temporal variation of concrete properties. Finally, discussions are presented regarding their suitability and limitations for field applications.

scholarly journals Delineating shallow Neogene deformation structures in northeastern Pará State using Ground Penetrating Radar

2003 ◽  
Vol 75 (2) ◽  
pp. 235-248 ◽  
Author(s):  
Dilce F. Rossetti
Keyword(s):  
Ground Penetrating Radar ◽  
Structural Models ◽  
Field Studies ◽  
Strike Slip ◽  
Brittle Deformation ◽  
Shallow Subsurface ◽  
Deformation Structures ◽  
Ground Penetrating ◽  
Slip Motion

The geological characterization of shallow subsurface Neogene deposits in northeastern Pará State using Ground Penetrating Radar (GPR) revealed normal and reverse faults, as well as folds, not yet well documented by field studies. The faults are identified mostly by steeply-dipping reflections that sharply cut the nearby reflections causing bed offsets, drags and rollovers. The folds are recognized by reflections that are highly undulating, configuring broad concave and convex-up features that are up to 50 m wide and 80 to 90 ns deep. These deformation structures are mostly developed within deposits of Miocene age, though some of the faults might continue into younger deposits as well. Although the studied GPR sections show several diffractions caused by trees, differential degrees of moisture, and underground artifacts, the structures recorded here can not be explained by any of these ''noises''. The detailed analysis of the GPR sections reveals that they are attributed to bed distortion caused by brittle deformation and folding. The record of faults and folds are not widespread in the Neogene deposits of the Bragantina area. These GPR data are in agreement with structural models, which have proposed a complex evolution including strike-slip motion for this area from the Miocene to present.

IN-SITU CASSAVA ROOT SIZE MEASUREMENT USING GROUND PENETRATING RADAR (GPR)

2018 ◽  
Author(s):  
Timothy H. Larson ◽  
Riley J. Balikian ◽  
Ursula Ruiz-Vera ◽  
Donald Ort
Keyword(s):  
Ground Penetrating Radar ◽  
Size Measurement ◽  
Cassava Root ◽  
Ground Penetrating ◽  
Root Size
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