Analysis of electromagnetic wave propagation in multilayered media using dyadic Green's functions

Cavalcante, Gervásio P. S.; Rogers, David A.; Giarola, A.J.

doi:10.1029/rs017i003p00503

Cited by 45 publications

(7 citation statements)

References 8 publications

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“…(marked by N in Figure 12). The transmission factor (T) and reflection factor (R) of electromagnetic waves are considered to be the same as those at normal incidence by equations (5a) and (5b) (Dos Santos Cavalcante et al, 1982).…”

Section: Simulation With the Transmission Line Modelmentioning

confidence: 99%

Underground Measurement of Magnetic Field Pulses During the Early Stage of Rocket‐Triggered Lightning

Fan

et al. 2019

JGR Atmospheres

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We examined the underground magnetic field near the lightning channel with low‐frequency magnetic sensor based on SHAndong Triggering Lightning Experiment (SHATLE). Two sensors were deployed, one at 1‐m height above ground and another one at 2‐m depth underground at a distance of 78 m from the lightning channel, and the magnetic pulses during the initial stage of triggered lightning were recorded. The experimental results show that the microsecond‐scale magnetic pulses radiated by the upward lightning leader can be detected in the subsurface space and the magnetic signal is modified by the soil medium. Specifically, the amplitude at the depth of 2 m is attenuated typically more than 55%, and the attenuation decreases as the timescale of the magnetic pulse increases; meanwhile, the peak time of the underground magnetic pulse is delayed by about 0.6 μs, and the half‐peak width of the magnetic pulse is increased by 0.2–0.8 μs (namely, by 20% to 32%). The results of Fourier analysis indicate that the component with relatively high frequency is subject to more attenuation than is the component with relatively low frequency. In addition, the simulation of magnetic field with the channel‐base current by using the transmission line model is consistent with the measurement, indicating that the modification on the waveform characteristics of the lightning pulse measured underground could provide valuable information for retrieving the electromagnetic parameters of soil.

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Section: Simulation With the Transmission Line Modelmentioning

confidence: 99%

Underground Measurement of Magnetic Field Pulses During the Early Stage of Rocket‐Triggered Lightning

Fan

et al. 2019

JGR Atmospheres

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“…(23) we found that as the number of meshes grows, the scattering cross section calculated by the collection of meshes in Eq. (25) converges to the initial value of one single mesh of Eq. (26).…”

Section: -3mentioning

confidence: 99%

“…11,[24][25][26][27][28][29][30] Our first task in this section is to arrive at an explicit expression for the scattered electric far field. This is attained by propagating the field induced by a dipole density P (1) (r ) = ε E r (r ) (where ε = ε − 1) inside the area of a ridge, to a point R very far from the source.…”

Section: Scattering Coefficientsmentioning

confidence: 99%

Comparative study of surface plasmon scattering by shallow ridges and grooves

Brucoli

Martín‐Moreno

2011

Phys. Rev. B

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We revisit the scattering of surface plasmons by shallow surface defects for both protrusions and indentations of various lengths, which are deemed infinite in one dimension parallel to the surface. Subwavelength protrusions and indentations of equal shape present different scattering coefficients when their height and width are comparable. In this case, a protrusion scatters plasmons like a vertical point dipole on a metal surface, while an indentation scatters like a horizontal point dipole on a metal surface. We corroborate that long and shallow asymmetrically shaped surface defects have very similar scattering coefficients, as already found with approximate methods. In the transition from short shallow scatterers to long shallow scatterers, the radiation can be understood in terms of interference between a vertical and a horizontal dipole. The results attained numerically are exact and accounted for with analytical models.

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“…However, as first pointed out by Sommerfeld [1964], in order to satisfy the interfacial conditions in a layered medium, the vector potential used by MPIE due to vertical current source (perpendicular to layer interfaces) must be different from that due to a horizontal current source. Thus, a choice has to be made for the dyadic Green's function between the Sommerfeld potential and transverse potential [dos Santos Cavalcante et al, 1982;Michalski and Zheng, 1990;Cai and Yu, 2000]. To remedy the problem, the use of transverse electric/ magnetic (TE/TM) scalar potentials can provide the complete solution for a layered medium without strolling between these two types of dyadic Green's functions as shown by YlaOijala et al [2001].…”

Section: Introductionmentioning

confidence: 99%

Field forms of the layered electromagnetic Green's functions by TE and TM potentials

Cao

Guzina

2011

Radio Science

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[1] A complete set of 3D layered electromagnetic Green's functions in the spatial domain is derived by way of transverse electric and transverse magnetic potentials, featuring a "direct" formulation for the field forms of the spectral Green's functions. The improper integrals underpinning the computation of the corresponding point-load solutions in the spatial domain are evaluated via the method of asymptotic decomposition, wherein the singular behaviors are entirely extracted and integrated analytically-so that the remaining residual components can be computed effectively and accurately via adaptive numerical quadrature over a suitable contour path. It is also found that, in the spectral domain, the decay of the (numerically-integrated) residual field forms is commensurate with that of their potential-form counterparts, which eliminates the perceived gap between the computation of the field forms and respective potential forms of the Green's functions in the spatial domain. The effectiveness and accuracy of the proposed methodology is evaluated via comparison with relevant examples in the literature.Citation: Cao, Y., and B. B. Guzina (2011), Field forms of the layered electromagnetic Green's functions by TE and TM potentials, Radio Sci., 46, RS6003,

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Analysis of electromagnetic wave propagation in multilayered media using dyadic Green's functions

Cited by 45 publications

References 8 publications

Underground Measurement of Magnetic Field Pulses During the Early Stage of Rocket‐Triggered Lightning

Underground Measurement of Magnetic Field Pulses During the Early Stage of Rocket‐Triggered Lightning

Comparative study of surface plasmon scattering by shallow ridges and grooves

Field forms of the layered electromagnetic Green's functions by TE and TM potentials

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