Abstract
In this paper, we investigate the propagation of an ultra-wideband electromagnetic pulse in a homogeneous, cold plasma which is used to represent a simplified model of the atmosphere. The standard procedure for the computation of the corresponding transient field involves the application of a fast Fourier transform (FFT) to a well-known, analytical, frequency-domain solution. However, because of the long tails in both the time and frequency domains, a large number of sample points are required to compute the transient response using this FFT approach. In this paper, we introduce a new asymptotic extraction technique which dramatically reduces the number of sample points required by the FFT. First, we review the recently derived closed-form expression for a double-exponential pulse propagating in a homogeneous, collisionless, cold plasma. Since the high-frequency behavior does not depend on the electron collision frequency, an analytical frequency-domain expression, which is similar in form to the one encountered for the collisionless, cold plasma and encompasses this high-frequency behavior, can be subtracted from the exact expression for the plasma with a nonzero collision frequency. The extracted term is evaluated analytically. The remaining expression, which can be transformed to the time domain with a FFT, requires only a modest number of sample points. This dramatically improves the numerical efficiency of the approach. We find that the extracted analytical term provides a very good approximation for the early-time behavior of the transient pulse.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 239-250 |
| Number of pages | 12 |
| Journal | Radio Science |
| Volume | 32 |
| Issue number | 1 |
| State | Published - Jan 1997 |
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ASJC Scopus subject areas
- Computer Networks and Communications
- Atmospheric Science
- Computers in Earth Sciences
- Geochemistry and Petrology
- Geophysics
- Instrumentation
Cite this
Ultra-wideband electromagnetic pulse propagation in a homogeneous, cold plasma. / Dvorak, Steven L; Ziolkowski, Richard W; Dudley, Donald G.
In: Radio Science, Vol. 32, No. 1, 01.1997, p. 239-250.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Ultra-wideband electromagnetic pulse propagation in a homogeneous, cold plasma
AU - Dvorak, Steven L
AU - Ziolkowski, Richard W
AU - Dudley, Donald G.
PY - 1997/1
Y1 - 1997/1
N2 - In this paper, we investigate the propagation of an ultra-wideband electromagnetic pulse in a homogeneous, cold plasma which is used to represent a simplified model of the atmosphere. The standard procedure for the computation of the corresponding transient field involves the application of a fast Fourier transform (FFT) to a well-known, analytical, frequency-domain solution. However, because of the long tails in both the time and frequency domains, a large number of sample points are required to compute the transient response using this FFT approach. In this paper, we introduce a new asymptotic extraction technique which dramatically reduces the number of sample points required by the FFT. First, we review the recently derived closed-form expression for a double-exponential pulse propagating in a homogeneous, collisionless, cold plasma. Since the high-frequency behavior does not depend on the electron collision frequency, an analytical frequency-domain expression, which is similar in form to the one encountered for the collisionless, cold plasma and encompasses this high-frequency behavior, can be subtracted from the exact expression for the plasma with a nonzero collision frequency. The extracted term is evaluated analytically. The remaining expression, which can be transformed to the time domain with a FFT, requires only a modest number of sample points. This dramatically improves the numerical efficiency of the approach. We find that the extracted analytical term provides a very good approximation for the early-time behavior of the transient pulse.
AB - In this paper, we investigate the propagation of an ultra-wideband electromagnetic pulse in a homogeneous, cold plasma which is used to represent a simplified model of the atmosphere. The standard procedure for the computation of the corresponding transient field involves the application of a fast Fourier transform (FFT) to a well-known, analytical, frequency-domain solution. However, because of the long tails in both the time and frequency domains, a large number of sample points are required to compute the transient response using this FFT approach. In this paper, we introduce a new asymptotic extraction technique which dramatically reduces the number of sample points required by the FFT. First, we review the recently derived closed-form expression for a double-exponential pulse propagating in a homogeneous, collisionless, cold plasma. Since the high-frequency behavior does not depend on the electron collision frequency, an analytical frequency-domain expression, which is similar in form to the one encountered for the collisionless, cold plasma and encompasses this high-frequency behavior, can be subtracted from the exact expression for the plasma with a nonzero collision frequency. The extracted term is evaluated analytically. The remaining expression, which can be transformed to the time domain with a FFT, requires only a modest number of sample points. This dramatically improves the numerical efficiency of the approach. We find that the extracted analytical term provides a very good approximation for the early-time behavior of the transient pulse.
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M3 - Article
VL - 32
SP - 239
EP - 250
JO - Radio Science
JF - Radio Science
SN - 0048-6604
IS - 1
ER -