Oblique Sounding of the Ionosphere by Means of an Ionosonde–Direction Finder with Chirp Signal

Vertogradov, G. G.; Uryadov, V. P.; Sklyarevsky, M. S.; Valov, V. A.

doi:10.1007/s11141-017-9759-1

Cited by 7 publications

(3 citation statements)

References 9 publications

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“…The ISTP transmitters are located near Khabarovsk (47.6°N, 134.7°E), Magadan (60°N, 150.7°E), and Norilsk (69.2°N, 88°E), while the receiver is located near settlement Tory (51.8°N, 103°E), Buryatia (Figure ). The Cyprus transmitter (35°N, 34°E) is equipped by the chirp sounder with the sweep rate of 100 kHz/s, the frequency range of 8–32 MHz (Vertogradov et al, ), and intervals between soundings of 15 min. The path lengths are 3,100, 2,300, 2,200, and 5,700 km for Magadan‐Tory, Khabarovsk‐Tory, Norilsk‐Tory, and Cyprus‐Tory paths, respectively.…”

Section: Methodsmentioning

confidence: 99%

The 6 September 2017 X‐Class Solar Flares and Their Impacts on the Ionosphere, GNSS, and HF Radio Wave Propagation

et al. 2018

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On 6 September 2017, the Sun emitted two significant solar flares (SFs). The first SF, classified X2.2, peaked at 09:10 UT. The second one, X9.3, which is the most intensive SF in the current solar cycle, peaked at 12:02 UT and was accompanied by solar radio emission. In this work, we study ionospheric response to the two X‐class SFs and their impact on the Global Navigation Satellite Systems and high‐frequency (HF) propagation. In the ionospheric absolute vertical total electron content (TEC), the X2.2 SF caused an overall increase of 2–4 TECU on the dayside. The X9.3 SF produced a sudden increase of ~8–10 TECU at midlatitudes and of ~15–16 TECU enhancement at low latitudes. These vertical TEC enhancements lasted longer than the duration of the EUV emission. In TEC variations within 2–20 min range, the two SFs provoked sudden increases of ~0.2 TECU and 1.3 TECU. Variations in TEC from geostationary and GPS/GLONASS satellites show similar results with TEC derivative of ~1.3–1.7 TECU/min for X9.3 and 0.18–0.24 TECU/min for X2.2 in the subsolar region. Further, analysis of the impact of the two SFs on the Global Navigation Satellite Systems‐based navigation showed that the SF did not cause losses‐of‐lock in the GPS, GLONASS, or Galileo systems, while the positioning error increased by ~3 times in GPS precise point positioning solution. The two X‐class SFs had an impact on HF radio wave propagation causing blackouts at <30 MHz in the subsolar region and <15 MHz in the postmidday sector.

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Section: Methodsmentioning

confidence: 99%

The 6 September 2017 X‐Class Solar Flares and Their Impacts on the Ionosphere, GNSS, and HF Radio Wave Propagation

et al. 2018

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“…The selected platform (SDRlab 122-16) provides the possibility of combining and synchronizing several boards [30]. Therefore, multichannel registration of ionograms using phased antenna arrays can be implemented, which will allow determining the polarization and the angle of arrival of signals reflected from the ionosphere [31,32]. Since the ION-FAST ionosonde has two receiving channels, it is possible to measure the frequency dependences of the Doppler frequency shifts of each ionospheric mode [33] without additional hardware upgrades.…”

Section: Discussionmentioning

confidence: 99%

ION-FAST as the NIRFI’s Ionospheric Diagnostic Platform

Moiseev,

Shindin,

Grekhneva

et al. 2024

Atmosphere

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In December 2021, we presented a prototype of a fast ionosonde for vertical sounding based on the usage of publicly available radio-electronic components. This approach led to a major reduction in the cost of the created device. We called our development ION-FAST, which characterizes the key feature of the ionosonde: the possibility of continuous operation at a speed of one ionogram per second, which is required to study the rapid processes of redistribution of the electron concentration during heating experiments. In May 2022, an ionosonde for vertical sounding of the ionosphere, developed at the Radiophysical Research Institute of Nizhni Novgorod (NIRFI), was put into continuous operation at the SURA facility. This report provides a description of the improvements made to the prototype over the last year and the path to be passed from idea to implementation. The results of the first months of the prototype’s operation (especially the results of the supporting optic experiment in August 2022), as well as prospects for further use and modernization, are provided. In addition, the realization of the oblique chirp-sounding receiver prototype as an extension of the proposed diagnostic platform’s functionality, including the first results, is presented.

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“…• Periodic and quasi-periodic TIDs will cause various horizontal gradients to appear in the ionosphere, thus causing the direction of arrival to deviate from the spherical mirror model [14], [15]. • At dawn and dusk, the passage of the solar terminator causes large gradients in the ionosphere, and thus deviations in direction of arrival [16]. • At longer ground ranges, variations in the ionosphere will be more pronounced and the SMM's core assumption of a spherically symmetric ionosphere will be less accurate.…”

Section: Direction Of Arrivalmentioning

confidence: 99%

Response of a Polarimetric Antenna to Ionospherically Propagated Signals

Pederick

Harris

MacKinnon

2021

IEEE Trans. Antennas Propagat.

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The Earth's magnetic field causes the ionosphere to be birefringent at radio frequencies, which means that any system using ionospherically propagated radio waves, such as long distance broadcasting, high frequency (HF) skywave communications, over-the-horizon radar and oblique incidence sounders (OIS), will receive pairs of waves with different polarizations. In this paper we develop a model for the polarization of ionospherically propagated radio waves; the polarization is dependent only upon the strength and direction of the magnetic field at the location where the radio wave exits the ionosphere. This leads to the hemisphere of possible incoming directions of arrival to any particular receiver being divided into three distinct regions. We then use this model to predict the response of a polarimetric antenna to a transmitted OIS signal, and validate the model against real ionograms, including cases where all three polarization regions can be clearly observed.

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Oblique Sounding of the Ionosphere by Means of an Ionosonde–Direction Finder with Chirp Signal

Cited by 7 publications

References 9 publications

The 6 September 2017 X‐Class Solar Flares and Their Impacts on the Ionosphere, GNSS, and HF Radio Wave Propagation

The 6 September 2017 X‐Class Solar Flares and Their Impacts on the Ionosphere, GNSS, and HF Radio Wave Propagation

ION-FAST as the NIRFI’s Ionospheric Diagnostic Platform

Response of a Polarimetric Antenna to Ionospherically Propagated Signals

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