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Ground-Penetrating Radar Theory And Application Of Thin-Bed Offset-Dependent Reflectivity, John H. Bradford, Jacob C. Deeds
Ground-Penetrating Radar Theory And Application Of Thin-Bed Offset-Dependent Reflectivity, John H. Bradford, Jacob C. Deeds
CGISS Publications and Presentations
Offset-dependent reflectivity or amplitude-variationwith- offset (AVO) analysis of ground-penetrating radar (GPR) data may improve the resolution of subsurface dielectric permittivity estimates. A horizontally stratified medium has a limiting layer thickness below which thin-bed AVO analysis is necessary. For a typical GPR signal, this limit is approximately 0.75 of the characteristic wavelength of the signal. Our approach to modeling the GPR thin-bed response is a broadband, frequency-dependent computation that utilizes an analytical solution to the three-interface reflectivity and is easy to implement for either transverse electric (TE) or transverse magnetic (TM) polarizations. The AVO curves for TE and TM modes differ …
Investigating The Stratigraphy Of An Alluvial Aquifer Using Crosswell Seismic Traveltime Tomography, Geoff J.M. Moret, Michael D. Knoll, Warren Barrash, William P. Clement
Investigating The Stratigraphy Of An Alluvial Aquifer Using Crosswell Seismic Traveltime Tomography, Geoff J.M. Moret, Michael D. Knoll, Warren Barrash, William P. Clement
CGISS Publications and Presentations
In this study, we investigate the use of crosswell P-wave seismic tomography to obtain spatially extensive information about subsurface sedimentary architecture and heterogeneity in alluvial aquifers. Our field site was a research wellfield in an unconfined aquifer near Boise, Idaho. The aquifer consists of a ~ 20-m-thick sequence of alluvial cobble- and-sand deposits, which have been subdivided into five stratigraphic units based on neutron porosity logs, grainsize analysis, and radar reflection data. We collected crosswell and borehole-to-surface seismic data in wells 17.1 m apart. We carefully considered the impact of well deviation, data quality control, and the choice of inversion …