All Figures

$\begin{figure} \par\includegraphics[width=8.2cm,clip]{4386fig1.eps}\end{figure}$ Figure 1: The 1D electron density structure (expressed in the scale of the corresponding plasma frequency) in the form of a finite series of periodically repeating square-shaped wells of depth $\Delta \omega _{\rm p}$ and of period 2a. An electromagnetic wave with the angular frequency $\omega >\omega _{\rm p0}$ comes from the left and is partly transmitted and partly reflected. Two cases were studied: the background density is homogeneous (the solid line), and the background density drops by $\Delta \omega _{\rm p}$ behind the structure (the dashed line on the right).
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In the text

$\begin{figure} \par\includegraphics[width=6.2cm,clip]{4386fig2.eps}\end{figure}$ Figure 2: Two alternative ray paths leading to a modulation in the frequency: a) the filtration via transmission through (regular) density structure, b) the Bragg-like reflections on (regular) density structure.
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In the text

$\begin{figure} \par\includegraphics[width=14cm,clip]{4386fig3.eps}\end{figure}$ Figure 3: The transmission coefficient T for the single density well as a function of the frequency of an incident wave for the parameters given in the text. Two approximations are compared. Left: calculation based on solution of the approximate Eq. (2); right: calculation based on exact solution of Eq. (1).
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In the text

$\begin{figure} \par\includegraphics[width=6.8cm,clip]{4386fig4.eps}\end{figure}$ Figure 4: The reflection coefficient R=1-T for the series of 50 density wells finished by the density drop as a function of the frequency of an incident wave. See text for parameters.
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In the text

$\begin{figure} \par\includegraphics[width=6.8cm,clip]{4386fig5.eps}\end{figure}$ Figure 5: The theoretically predicted density profile around the ion-sound shock wavefront in the shock reference frame calculated using the Sagdeev potential approach (Sagdeev 1966). The whole structure moves to left relative to ambient plasma at the speed given by Mach number M=1.2.
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In the text

$\begin{figure} \par\includegraphics[width=6.7cm,clip]{4386fig6.eps}\end{figure}$ Figure 6: Spectrum of the broad-band continuum of an originally Gaussian spectral profile after the filtration via transmission through the single density well. See text for parameters.
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In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{4386fig7.eps}\end{figure}$ Figure 7: The zebra pattern observed on May 2, 1998 in the decimetric range by the Ondrejov radiospectrograph. The dynamic spectrum ( left) and frequency profile at 14:29:27.3 UT ( right) are shown.
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In the text

$\begin{figure} \par\includegraphics[width=6.2cm,clip]{4386fig2.eps}\end{figure}$	Figure 2: Two alternative ray paths leading to a modulation in the frequency: a) the filtration via transmission through (regular) density structure, b) the Bragg-like reflections on (regular) density structure.
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$\begin{figure} \par\includegraphics[width=14cm,clip]{4386fig3.eps}\end{figure}$	Figure 3: The transmission coefficient T for the single density well as a function of the frequency of an incident wave for the parameters given in the text. Two approximations are compared. Left: calculation based on solution of the approximate Eq. (2); right: calculation based on exact solution of Eq. (1).
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$\begin{figure} \par\includegraphics[width=6.8cm,clip]{4386fig4.eps}\end{figure}$	Figure 4: The reflection coefficient R=1-T for the series of 50 density wells finished by the density drop as a function of the frequency of an incident wave. See text for parameters.
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$\begin{figure} \par\includegraphics[width=6.8cm,clip]{4386fig5.eps}\end{figure}$	Figure 5: The theoretically predicted density profile around the ion-sound shock wavefront in the shock reference frame calculated using the Sagdeev potential approach (Sagdeev 1966). The whole structure moves to left relative to ambient plasma at the speed given by Mach number M=1.2.
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$\begin{figure} \par\includegraphics[width=6.7cm,clip]{4386fig6.eps}\end{figure}$	Figure 6: Spectrum of the broad-band continuum of an originally Gaussian spectral profile after the filtration via transmission through the single density well. See text for parameters.
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$\begin{figure} \par\includegraphics[width=7.5cm,clip]{4386fig7.eps}\end{figure}$	Figure 7: The zebra pattern observed on May 2, 1998 in the decimetric range by the Ondrejov radiospectrograph. The dynamic spectrum ( left) and frequency profile at 14:29:27.3 UT ( right) are shown.
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