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SHAREABLE DATA CENTER
East Siberian Center for the Earth's Ionosphere Research (SDC ESCEIR)Institute of Solar-Terrestial Physics SB RASUpper Atmosphere Physics and Radiowave Propagation Department |
Composition
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Incoherent scatter ionosphere diagnostics subdivisionSpecific character ionosphere parameters measurements with the Irkutsk IS radarIn spite of the good potential possibilities, some of the station "Dnepr" design characteristics did not allow us to apply the usual special IS radar measurement methods. One of them is the design the station's antenna system, which excites and receives the linearly-polarized field. The Faraday effect causes the polarization vector to rotate, which leads to periodical signal fadings at the receiver input. Special purpose the IS radars usually measure two orthogonal polarizations to avoid this effect or they radiate and receive circularly polarized radiowaves. Thus for IS signal measurements at the "Dnepr" station, we have developed special methods for recording and processing IS signals in order to determine plasma ionospheric parameters. |
To solve this problem on the basis of the electromagnetic wave scattering statistical theory we have obtained the IS radar equation with Faraday effect. This equation gives us an opportunity to apply the IS method at radars with linear polarized antennas. The spectral density of the IS signal has the form:
where
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The radar equation for the IS signal power with a given height is obtained by integration of
where re -- classical electron radius, and that
where |
The desired ionospheric plasma parameters Ne, Te, Ti, and Vd, defining the fluctuation density The value of
where |
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Equations (4-5) from the basis for data post processing to obtain ionosphere parameters. On the one hand, the presence of one linear polarization gives rise to some complexity in algorithms for analyzing the IS signal by formulas (1-4); and, on the other, the determined character of polarization plane rotation gives us an opportunity to make absolute calibration of the electron density, while at the other radars one needs to use ionosonde data. In our case, the electron density is determined from equation (4), which gives a one-to-one correspondence between the polarization phase and electron density. |