Ground‐penetratinng radar reflection profiling of groundwater and bedrock in an area of discontinuous permafrost

Geophysics ◽  
1998 ◽  
Vol 63 (5) ◽  
pp. 1573-1584 ◽  
Author(s):  
Steven A. Arcone ◽  
Daniel E. Lawson ◽  
Allan J. Delaney ◽  
Jeffrey C. Strasser ◽  
Jodie D. Strasser
Keyword(s):  
Ground Penetrating Radar ◽  
Relative Dielectric Permittivity ◽  
Well Log ◽  
Surface Conditions ◽  
Continuous Contact ◽  
Interior Alaska ◽  
Discontinuous Permafrost ◽  
Radar Reflection ◽  
Ground Penetrating ◽  
Scattering Losses

We have used ground‐penetrating radar to profile the depth of permafrost, to groundwater beneath permafrost, and to bedrock within permafrost in alluvial sediments of interior Alaska. We used well log data to aid the interpretations and to calculate dielectric permittivities for frozen and unfrozen materials. Interfaces between unfrozen and frozen sediments above permafrost were best resolved with wavelet bandwidths centered at and above 100 MHz. The resolution also required consideration of antenna configuration, season, and surface conditions. Depths to subpermafrost groundwater were profiled where it was in continuous contact with the bottom of the permafrost, except near transitions to unfrozen zones, where the contact appeared to dip steeply. The complexity of the responses to intrapermafrost bedrock, detected at a maximum depth of 47 m, appears to distinguish these events from those of subpermafrost saturated sediments. The relative dielectric permittivity ranged between 4.4 and 8.3 for the permafrost, and between 12 and 45 for partially to fully saturated, unfrozen silts and sands. Scattering losses are evident from intrapermafrost diffractions and from the improved penetration achieved by lowering the midband radar frequency from 100 to 50 MHz.

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.

Mapping vertical profile of discontinuous permafrost with ground penetrating radar at Nalaikh depression, Mongolia

2008 ◽  
Vol 56 (8) ◽  
pp. 1577-1583 ◽  
Author(s):  
Tonghua Wu ◽  
Qinxue Wang ◽  
Masataka Watanabe ◽  
Ji Chen ◽  
Dorjgotov Battogtokh
Keyword(s):  
Ground Penetrating Radar ◽  
Vertical Profile ◽  
Discontinuous Permafrost ◽  
Ground Penetrating

scholarly journals Performance of Soil Water Content Using Ground Penetrating Radar with Different Antenna Frequencies

2018 ◽  
Vol 7 (2.29) ◽  
pp. 815
Author(s):  
Nurul Izzati Abd Karim ◽  
Samira Albati Kamaruddin ◽  
Rozaimi Che Hasan
Keyword(s):  
Dielectric Permittivity ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Ground Penetrating Radar ◽  
Peat Soil ◽  
Relative Dielectric Permittivity ◽  
Depth Of Penetration ◽  
Engineering Research ◽  
Ground Penetrating

Accurate measurements of Soil Water Content (SWC) with applicable and relevant support are essential in many fields of earth and soil engineering research. Ground Penetrating Radar (GPR) is a geophysical tool that measures and provides accurate results for determination of the SWC. To prove the accuracy of SWC measurement using GPR, a field survey was performed in peat soil. This paper presents a fieldwork survey with the aim of assessing the SWC measurement using GPR. The survey work was conducted at Johor Bharu using different antenna frequencies (250 and 700 MHz). Five profiles, which is 5m by 5m in length, were scanned along an east-west direction with a common offset at an equal spacing of 1m.  To measure the SWC using GPR, the researchers used the velocity from the GPR’s signal from the receiving antenna to the soil. Statistical analysis was carried out based on the dielectric permittivity and SWC. Schaap’s equation and Roth’s equation were used to distinguish the relative dielectric permittivity of the soil to SWC. The results of this study show the linear function,  for the measured SWC. The validation graph shows that at a frequency of 250 MHz, the depth of penetration was greater compared to the frequency of 750 MHz. These results, suggest that a higher frequency will give higher resolution but lower depth penetration.  

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