Natalia V. Ryabova

Research of dispersion distortion of signals in the ionospheric plasma and optical fiber

Technique of research the dispersion distortion of wideband chirp signal elements was proposed and theoretically justified. It is shown that in a first approximation, the difference frequency element signal assumes a linear frequency modulation. A formula that relates the rate of change of frequency characteristics of the signal and the dispersion properties of the medium was derived.

Fiber material dispersion effect on a matched compression of an optical pulse with frequency modulation

The paper discusses the questions of creating a mathematical model for studying the extension of a broadband pulse caused by material dispersion of an optical fiber while matched compression is also taken into account. It was shown the dependence of the dispersion widening of optical broadband signal on the optical fiber material dispersion coefficient. It was established that we can neglect dispersion impact in the case when the pulse frequency band is less than the coherence band of an optical fiber.

Optical frequency modulated pulse power losses, caused by optical fiber material dispersion

The equations were obtained to estimate the pulse power losses of broadband light pulses caused by material dispersion in an optical fiber. It was found that the dispersion caused by the extension of a signal bandwidth leads to decreasing a signal base as well as the noise immunity of a system, which uses broadband pulses.

The plotting algorithm of coherence band maps of transionospheric radio channels

The paper presents the algorithm and software for plotting coherence bands maps of transionospheric radio channels using NavGeoKom network stations data. The results of full-scale experiments of mapping for various regions of the Russian Federation are shown.

Determining method of electronic concentration total profile using oblique and transionospheric sounding data

Paper shows a method for plotting the electron concentration profile of the ionosphere on the basis of a joint approach using oblique and transionospheric sounding data. The method of determining the profile up to the global maximum height is based on the reconstruction of oblique sounding ionograms. Above the maximum, an exponential layer model is used, the initial parameters of which are transionospheric sounding data.

A compression of light pulse in an optical fiber

This paper focuses on the technology of compression of light pulse in an optical fiber. Investigated the effects of compression and decompression of the optical linear chirp pulse and define the parameters of optimal pulse. Simulated the rectangular chirp light pulse at different ratios between the parameters of the phase and frequency change.