The results of operative diagnostics for ionosphere on the base of backscatter sounding received via chirp ionosonde are presented. The results of identification for registered signals and creation of tracks are basic data for determination of maximum usable frequencies and distant-frequency characteristics of one-hop mode 1F2 for oblique propagation on the given grid of ranges, restoration of ionosphere parameters in the direction of sounding. The algorithm for transformation of the received characteristics for oblique sounding to the height-frequency characteristic of vertical sounding with the subsequent restoration of electronic concentration profile is realized.
We present techniques and algorithms for processing and interpretation of backscatter ionosphere sounding ionograms received on chirp ionosonde. The processing of experimental ionograms is carried out on the basis of basic data filtration with the subsequent compression by method of the cellular automaton. The interpretation technique for ionograms is based on use of modeling results for frequency dependences on the minimum group way in the mode of the long-term forecast and results of experimental data processing. We also present the results of operative diagnostics of HF radio channel on the base of current backscatter sounding data.
The results for modeling of HF radio waves propagation characteristics are given for the periods of solar flares 25.02.2014, 25.10.2013, 13-14.05.2013. The distance–frequency and amplitude-frequency propagation characteristics are calculated on the base of the complex algorithm which includes modules of ionosphere and plasmasphere global models and radio waves propagation model. The results of calculations were compared with experimental data of oblique ionosphere sounding obtained by chirp ionosonde on paths Magadan – Irkutsk, Khabarovsk – Irkutsk and Norilsk – Irkutsk.
The disturbances of ionospheric radio channel during 17–24 March 2015 magnetic storm are investigated. The heliospheric sources which caused the storm are considered. Based on space-distributed multipurpose chirp ionosonde data effects of geomagnetic disturbances influence on conditions of HF signal propagation are studied.
The paper deals with techniques and algorithms of near real-time diagnostic software for estimating ionospheric parameters at a radio path midpoint based on data obtained from oblique sounding by a continuous chirp signal. We conducted a statistical analysis of precision characteristics of automatic determination of the critical frequency <i>f<sub>0</sub>F2</i> at the path midpoint, using chirp ionosonde data.
On the base of the space-distributed multipurpose chirp ionosonde effects of solar flare influence on conditions of HF signals distribution in the northeast region of Russia were registered on February 25, 2014. The absorption increase in D – ionosphere areas during flare due to splash in x-ray radiation was shown in disappearance of the signals corresponding to modes with multiple reflections from ionospheric layer both for the ionograms of oblique and vertical sounding. In the period of a magnetic storm on February 27, 2014 on the oblique sounding ionograms on paths Magadan – Irkutsk and Khabarovsk – Irkutsk in evening and night hours of local time, were observed additional signals with abnormally big delay. The amplitude relief of abnormal signals was characterized by strong diffusion, and frequencies exceeded the maximal observed frequencies of standard propagation modes.