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1.
N. P. Danilkin S. V. Zhuravlev N. G. Kotonaeva V. B. Lapshin I. V. Romanov M. Y. Filippov E. N. Khotenko G. A. Zhbankov 《Solar System Research》2018,52(7):684-690
The satellite ionosondes in highly elliptical orbits are proposed to be used for the task of continuous monitoring of the Arctic ionosphere. The monitoring scheme with the ionosonde location aboard the Arktika-M satellites is presented. The calculations of the vertical topside and transionospheric sounding using the SIMP1 ionospheric model are performed, which show the feasibility of continuous monitoring. 相似文献
2.
Complex ionograms from the Intercosmos-19 satellite with strongly delayed and sometimes multiple reflections from the Earth are considered. An analysis shows that these reflections are usually associated with sharp horizontal gradients of the ionospheric plasma. Such gradients are formed on the walls of the main ionospheric trough, at peaks of electron density, and on the inner and, especially frequently, on the outer slope of the crest of the equatorial anomaly. In one case, distant reflections from the Earth (DREs) formed near the equator, when the satellite in perigee was lower than the F2-layer maximum height. A quantitative interpretation of the most typical cases of DREs is given based on ray tracing. For this purpose, the model of the ionosphere under the satellite is developed, ray paths are calculated, and model ionograms are formed. The good agreement between experimental and model ionograms allows us to conclude that the task of interpreting complicated ionograms obtained by Intercosmos-19 with DRE has been solved successfully. 相似文献
3.
V. A. Panchenko V. A. Telegin V. G. Vorob’ev G. A. Zhbankov O. I. Yagodkina V. I. Rozhdestvenskaya 《Geomagnetism and Aeronomy》2018,58(2):229-236
The results of studying spread F obtained from the DPS-4 ionosonde data at the observatory of the Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation (Moscow) are presented. The methodical questions that arise during the study of a spread F phenomenon in the ionosphere are considered; the current results of terrestrial observations are compared with previously published data and the results of sounding onboard an Earth-satellite vehicle. The automated algorithm for estimation of the intensity of frequency spread F, which was developed by the authors and was successfully verified via comparison of the data of the digisonde DPS-4 and the results of manual processing, is described. The algorithm makes it possible to quantify the intensity of spread F in megahertz (the dFs parameter) and in the number of points (0, 1, 2, 3). The strongest spread (3 points) is shown to be most likely around midnight, while the weakest spread (0 points) is highly likely to occur during the daytime. The diurnal distribution of a 1–2 point spread F in the winter indicates the presence of additional maxima at 0300–0600 UT and 1400–1700 UT, which may appear due to the terminator. Despite the large volume of processed data, we can not definitively state that the appearance of spread F depends on the magnetic activity indices Kp, Dst, and AL, although the values of the dFs frequency spread interval strongly increased both at day and night during the magnetic storm of March 17–22, 2015, especially in the phase of storm recovery on March 20–22. 相似文献
4.
Geomagnetism and Aeronomy - Additional horizontal traces of ground reflections were observed in a studied series of high-latitude, Kp sounding ionograms from the Interkosmos-19 satellite. The... 相似文献
5.
A comparison of the total electron content (TEC) of the ionosphere calculated using different correcting multipliers in the
IRI2007 model with experimental data indicates that this model, which is not empirical with respect to the TEC, does not adequately
reflect the quantitative and qualitative features of the TEC behavior. The situation can be improved by using new empirical
models of the critical frequency and equivalent thickness of the ionosphere and new methods for determining the TEC. 相似文献
6.
Complicated ionograms of topside sounding on board the Intercosmos-19 satellite, which were registered on November 26, 1980,
in the dusk sector (1800 LT) at the latitudes of the equatorward wall (55°–62° ILAT) of the main ionospheric trough (MIT),
are analyzed. They are characterized by the presence of two extra traces at distances larger than the main traces. Approaching
the MIT minimum, all traces become more scattered, converge, and join into one strongly diffusive trace. An attempt of interpretation
of the complicated ionograms on the basis of trajectory calculations performed by the method of characteristics in the “complex”
two-dimensional version (in two mutually intersecting planes) is undertaken. The modeling shows that the extra traces could
be related to the presence of a large-scale irregularity stretched along the geomagnetic meridian at the equatorward wall
of the MIT. The calculations make it possible to estimate the parameters of the irregularity: the intensity is δfoF2 ∼ 30%, the length is several hundred kilometers, the semi-thickness is 50–60 km, and the height is 350 km. The possible
formation causes of the irregularity are discussed. The intensification of the diffuseness of all traces is related to the
increase in the intensity of small-scale irregularities, which is usually observed when approaching the MIT minimum. 相似文献
7.
Geomagnetism and Aeronomy - Empirical median models of the ionosphere are widely used to predict the propagation of high-frequency radio waves. Their adaptation to the real state of the ionosphere... 相似文献
8.
With the use of data from topside sounding on board the Interkosmos-19 (IK-19) satellite, the region of permanent generation of large-scale irregularities in the daytime winter ionosphere of the Southern Hemisphere is differentiated. This region is characterized by low values of foF2 and hmF2 and occupies a rather large latitudinal band, from the equatorial anomaly ridge to ~70° S within the longitudinal range from 180° to 360°. Irregularities with a dimension of hundreds kilometers are regularly observed in the period from 0700–0800 to 1800–1900 LT, i.e., mainly in the daytime. In the IK-19 ionograms, they normally appear in the form of an extra trace with a critical frequency higher than that of the main trace reflected from the ionosphere with lower density. The electron density in the irregularity maximum sometimes exceeds the density of the background ionosphere by nearly a factor of 3. A model of the ionosphere with allowance for its irregular structure was created, and it was shown on the basis of trajectory calculations how the IK-19 ionograms related to these irregularities are formed. A possible mechanism of the generation of large-scale irregularities of the ionospheric plasma is discussed. 相似文献
9.
Unusual complex ionograms obtained by the Intercosmos-19 satellite are considered, in which four diffuse clouds with a characteristic shape are strung like pearls on the main path of the reflected signal. Ray tracing has been used to show that they are associated with 26 layers of irregularities located at altitudes from hmFs2 up to ~900 km. The sizes of the irregularities range from a few kilometers to 100 kilometers, and the intensity of δNe reaches 100%. The heights of irregular layers increase towards the equator, together with a rise of the F2 layer, and are not associated with magnetic field lines. Complex ionograms have been observed on the outer slope and at the top of the crest of the equatorial anomaly. They are probably caused by the processes occurring in the equatorial ionosphere. 相似文献
10.
G. A. Zhbankov A. T. Karpachev V. A. Telegin K. G. Tsybulya 《Geomagnetism and Aeronomy》2010,50(1):119-126
It has been indicated how a complex ionogram of topside sounding near the outer slope of the winter southern crest of the
equatorial anomaly, where a large NmF2, gradient and a deep hmF2, minimum are observed, is formed. The model latitudinal cross-sectio n of the ionosphere, used to perform trajectory calculations,
has been constructed based on the corrected Intercosmos-19 data. The ray trajectories have been modeled using the method of
characteristics. It has been indicated that a complex Intercosmos-19 ionogram is formed by an oblique reflection from the
equatorial anomaly crest slope (the main trace) and by a strongly oblique reflection from the crest bottom as a result of
the wave capture by a large-scale inhomogeneity (the additional trace). 相似文献