The electromagnetic radiation from a finite antenna

Uman, M. A.; McLain, D. Kenneth; Krider, E. Philip

doi:10.1119/1.10027

Cited by 471 publications

(319 citation statements)

References 0 publications

Supporting

Mentioning

307

Contrasting

Unclassified

Order By: Relevance

“…distance [22]. For times after 0.4 µs, the closer dE/dt waveforms at 170 and 240 m show a hump that is likely associated with the electrostatic and intermediate electric field components as defined by Uman et al [23]. Fig.…”

Section: B Currents Induced In the Vertical Conductor During Rockettmentioning

confidence: 99%

Experimental Study of Lightning-Induced Currents in a Buried Loop Conductor and a Grounded Vertical Conductor

Schoene

Uman

Rakov

et al. 2008

IEEE Trans. Electromagn. Compat.

Self Cite

View full text Add to dashboard Cite

show abstract

Section: B Currents Induced In the Vertical Conductor During Rockettmentioning

confidence: 99%

Experimental Study of Lightning-Induced Currents in a Buried Loop Conductor and a Grounded Vertical Conductor

Schoene

Uman

Rakov

et al. 2008

IEEE Trans. Electromagn. Compat.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Figure 2. Waveforms of (a) H φ at r = 5 km, (b) E z at r = 5 km, (c) H φ at r = 200 km, and (d) E z at r = 200 km computed using the FDTD method for a lightning strike to flat, perfectly conducting ground and those computed with exact theoretical expressions of Uman et al [1975]. The lightning return stroke is represented by the MTLL model.…”

Section: Modelmentioning

confidence: 99%

“…These estimations are based on the measured magnetic or electric fields produced by lightning. When the ground is flat, perfectly conducting and the lightning channel is vertical, the relations between the magnitudes of lightning current peak I peak and the corresponding peaks of radiation components of electric and magnetic fields, E z, peak and H φ, peak , based on the transmission line model are given as follows [Uman et al, 1975]:…”

Section: Introductionmentioning

confidence: 99%

FDTD simulation of LEMP propagation over lossy ground: Influence of distance, ground conductivity, and source parameters

2015

View full text Add to dashboard Cite

We have computed lightning electromagnetic pulses (LEMPs), including the azimuthal magnetic field H φ , vertical electric field E z , and horizontal (radial) electric field E h that propagated over 5 to 200 km of flat lossy ground, using the finite difference time domain (FDTD) method in the 2-D cylindrical coordinate system. This is the first systematic full-wave study of LEMP propagation effects based on a realistic return-stroke model and including the complete return-stroke frequency range. Influences of the return-stroke wavefront speed (ranging from c/2 to c, where c is the speed of light), current risetime (ranging from 0.5 to 5 μs), and ground conductivity (ranging from 0.1 mS/m to ∞) on H φ , E z , and E h have been investigated. Also, the FDTD-computed waveforms of E h have been compared with the corresponding ones computed using the Cooray-Rubinstein formula. Peaks of H φ , E z , and E h are nearly proportional to the return-stroke wavefront speed. The peak of E h decreases with increasing current risetime, while those of H φ and E z are only slightly influenced by it. The peaks of H φ and E z are essentially independent of the ground conductivity at a distance of 5 km. Beyond this distance, they appreciably decrease relative to the perfectly conducting ground case, and the decrease is stronger for lower ground conductivity values. The peak of E h increases with decreasing ground conductivity. The computed E h /E z is consistent with measurements of Thomson et al. (1988). The observed decrease of E z peak and increase of E z risetime due to propagation over 200 km of Florida soil are reasonably well reproduced by the FDTD simulation with ground conductivity of 1 mS/m.

show abstract

“…All Rights Reserved. Uman et al [1975] used Maxwell's equations to derive an equation for the electric field E due to a current pulse traveling along a vertical conductor or antenna, i.e., a transmission line: Figure 3a shows the geometry of the problem. Here D is the horizontal distance from the antenna to the observation point, H 1 and H 2 are the altitudes of the beginning and end points of the discharge channel, and R = √ (z 2 + D 2 ) is the distance from the source to the observation point.…”

Section: Overview Of Modelingmentioning

confidence: 99%

Modeling initial breakdown pulses of CG lightning flashes

et al. 2014

View full text Add to dashboard Cite

Electric field change waveforms of initial breakdown pulses (IBPs) in cloud-to-ground (CG) lightning flashes were recorded at ten sites at Kennedy Space center, Florida, in 2011. Six "classic" IBPs were modeled using three modified transmission line (MTL) models called MTLL, MTLE, and MTLK. The locations of the six IBPs were obtained using a time-of-arrival method and used as inputs for the models; the recorded IBP waveforms from six to eight sites were used as model constraints. All three models were able to reasonably fit the measured IBP waveforms; the best fit was most often given by the MTLE model. For each individual IBP, there was good agreement between the three models on several physical parameters of the IBPs: current risetime, current falltime, current shape factor, current propagation speed, and the total charge moment change. For the six IBPs modeled, the ranges, mean values, and standard deviations of these quantities are as follows: current risetime

show abstract

The electromagnetic radiation from a finite antenna

Cited by 471 publications

References 0 publications

Experimental Study of Lightning-Induced Currents in a Buried Loop Conductor and a Grounded Vertical Conductor

Experimental Study of Lightning-Induced Currents in a Buried Loop Conductor and a Grounded Vertical Conductor

FDTD simulation of LEMP propagation over lossy ground: Influence of distance, ground conductivity, and source parameters

Modeling initial breakdown pulses of CG lightning flashes

Contact Info

Product

Resources

About