Experimentos laboratoriais com GPR (1GHz) em corpos arenosos para analisar a influência da água e de hidrocarbonetos na sua velocidade de propagação

Botelho, Marco A. Barsottelli; Machado, Sandro Lemos; Dourado, T C; Amparo, Nelson S.

doi:10.3997/2214-4609-pdb.168.arq_1021

Cited by 3 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Besides the reflection strength and traveltime (e.g. Botelho et al ), the presence of seawater and the NAPL saturation can be estimated by analysing the amplitude variations of the reflection event (Lehmann ; Baker ; Reppert et al ). Zeng et al presented synthetic AVO computations by varying the electromagnetic properties of a layer over a half‐space.…”

Section: Introductionmentioning

confidence: 99%

Fresnel reflection coefficients for GPR‐AVA analysis and detection of seawater and NAPL contaminants

Carcione

Gei

Botelho

et al. 2005

Near Surface Geophysics

View full text Add to dashboard Cite

We obtain the transverse electric (TE) and transverse magnetic (TM) Fresnel reflection coefficients for different interfaces in the subsoil: air/fresh‐water, air/seawater, fresh‐water/seawater, air/NAPL (non‐aqueous phase liquid), NAPL/water and water/NAPL. We consider a range of NAPL saturations, where the complementary fluid is water with 0.65 ppt (parts per thousand) of NaCl. The common feature is that the TM mode (parallel polarization) has a negative anomaly and the TE mode (perpendicular polarization) has a positive anomaly. For the cases studied in this work, pseudo‐Brewster angles appear beyond 40° for the air/NAPL and NAPL/water interfaces and at near offsets (below 40°) for the water/NAPL interface. Pseudo‐critical angles are present for the water/NAPL interface. Besides the reflection strength, the phase angle can be used to discriminate between low‐ and high‐conductivity NAPL, when the properties of the upper medium are known. A wavenumber–frequency domain method is used to compute the reflection coefficient and phase angle from synthetic radargrams. This method and the curves can be used to interpret the amplitude variations with angle (AVA) of reflection events in radargrams obtained with ground‐penetrating radar (GPR).

show abstract

Section: Introductionmentioning

confidence: 99%