We present the results of analysis of the dependence of the ionospheric airglow in the red (630 nm) and green (557.7 nm) lines of atomic oxygen on the pump-wave frequency
f
0
near the fourth electron ...gyroharmonic 4
f
ce
. The experimental data were obtained in 2012 using the SURA heating facility. Stimulated electromagnetic emission spectra were used to determine the relation between
f
0
and 4
f
ce
. It is found that at
f
0
> 4
f
ce
and
δf
=
f
0
− 4
f
ce
≈ 15–20 kHz the red-line airglow intensity is about a factor of 1.5 higher for the magnetic zenith pumping (when the pump beam is inclined 12° south of the magnetic field direction) than for the vertical pumping. In the green line for the same offsets
δf
, the airglow was recorded with confidence only during magnetic zenith pumping. During vertical pumping, no regular dependence of the red-line airglow intensity on
δf
in the range −15 <
δf
< 280 kHz was obtained, while the green-line airglow was observed at 15 <
δf
< +5 kHz and 230 <
δf
< 280 kHz. In the red line during vertical pumping, a change from the artificial airglow generation to the ionospheric background suppression was detected when the F-layer cutoff frequency was decreased. During magnetic zenith pumping, a wide (about 30°) background suppression zone was observed around the airglow spot with an about 6° angular width.
Abstract
A prototype of a low-cost GNSS receiver assembled on base of the u-blox ZED-F9P module is described in the paper. The original low-cost GNSS receiver (OGNSS-R) allows made the parallel ...registration of 184 channels in the entire frequency range (1176 ÷ 1610 MHz) of the main GNSS (GPS, GLONASS, Galileo, Beidou) and recording raw data of carrier-phase, pseudorange (code) and signal strength measurements. The obtained data processing allows to calculate the slant total electron content (TEC), TEC variations and other most popular TEC-based indices of ionospheric activity. The comparative studies of these parameters and similar parameters obtained by simultaneous measurements on the professional geodetic GNSS receiver Trimble Alloy (KZN2 station of the IGS network) were preformed. The analysis showed the median value of the signal strength at the L1 frequency for the KZN2 station are 8% higher than that at the low-cost GNSS receiver based on the u-blox ZED-F9P module (KZN2–48.75 dBHz; OGNSS-R – 45dBHz). For the L2 frequency that difference is less than 2% (KZN2–49.4 dBHz; OGNSS-R – 48.5 dBHz). The median levels of relative slant TEC and TEC-based indexes of the ionospheric activity obtained by the Trimble Alloy receiver at KZN2 station are 25÷50% lower than for the u-blox ZED-F9P receiver. Thus, the using of starter kits such as the simpleRTK2b debug board based on the u-blox ZED-F9P module described in the paper, is really actual for creating a permanent network of GNSS-stations and/or for carrying out field measurements in experimental campaigns.
Observations of the perturbations of total electron content (TEC) caused by a powerful radio emission of “Sura” facility (Radio Physical Research Institute, N. Novgorod) were carried out during ...several experimental campaigns from March of 2010 to March 2013. In this paper the data of experimental measurements of TEC-variations conducted on March, 15, 2010 and on March, 12, 2013, are presented. Parameters of TEC-variations were obtained by dual-frequency global navigation satellite systems (GNSS) diagnostics. Registration of signal parameters from GNSS-transmitters was performed at spatially separated sites along the geomagnetic latitude: Vasilsursk (56°08′N, 46°05′ E), Zelenodolsk (55°52′N, 48°33′E) and Kazan (55°48′N, 49°08′E). In the experiments radio path from GNSS satellite to Vasilsursk passed over the disturbed region of ionosphere, but radio paths to Zelenodolsk and to Kazan did not. However, TEC-variations correlated with pumping of ionosphere by “Sura” facility were detected for all up to three ground measurements sites. Magnitudes of TEC-variations reached up to ∼0.6–0.7 TECU. The speculation that a sharp gradient of the electron density formed at the border of the main lobe of “Sura” facility may cause the generation of IGW is presented.
We describe a method for joint analysis of the night-sky snapshots and total electron content (TEC) variation maps and present a dynamic spatiotemporal configuration of the TEC variation intensity in ...the ionospheric airglow region in the red line of atomic oxygen (λ = 630 nm) stimulated by high-power radio waves from the Sura facility. The measurements were performed on the 29th of August, 2016. Two-dimensional TEC variation maps were plotted according to a network of 30 GNSS stations located within a radius of 700 km from the Sura heater. It is shown that the region of the maximum brightness of the artificial ionospheric airglow spot is spatially localized in the region of the minimum intensity of TEC variations, while the region of the maximum intensity of TEC variations corresponds to the region of the minimum brightness of the artificial airglow spot. Quantitative estimates for a cavity with reduced electron density in the artificial airglow region, which forms after the Sura pump wave is switched on, vary in the range ΔN
e
/N
e
≈ 4–9%, where N
e
is the electron density and ΔN
e
is its variation in the cavity. The proposed experimental technique eliminates the limitations associated with the need for a navigation satellite to flyby directly over the main lobe of the Sura antenna pattern, which significantly increases the chances of successful simultaneous measurements of TEC variations and artificial ionospheric airglow in the 630 nm line.
The measurements of variations in the total electron content of the Earth’s ionosphere along the GPS satellite signal propagation path are described. The signal parameters were measured at a network ...of receivers at three distant sites: Sura (Vasilsursk), Zelenodolsk, and Kazan. They are arranged along the geomagnetic latitude of the Sura Facility under short-wave radio irradiation of the ionosphere. One feature of the experiment is the crossing of a disturbed region by the radio path between a GPS satellite and Vasilsursk. This resulted from the angular sizes of the Sura array pattern; the radio paths between a GPS satellite and Zelenodolsk and a GPS satellite and Kazan did not cross. Variations in the total electron content of up to 0.15−0.3 TECU were revealed at all three sites during four experimental campaigns (March 2010, March 2013, May 2013, and November 2013). The lateral scale of an ionospheric disturbance stimulated by a high-power radio wave and the velocity of its west-to-east propagation along the geomagnetic latitude were 30–60 km and 270–350 m/s, respectively. A decrease in the total electron content (down to 0.55 TECU) was recorded along the Kazan–Zelenodolsk–Vasilsurks line, which is connected with the solar terminator transit; the lateral scale of the related ionospheric inhomogeneities was ~65–80 km.
For the fermion transformation in the space all books of quantum mechanics propose to use the unitary operator \(\widehat{U}_{\vec n}(\varphi)=\exp{(-i\frac\varphi2(\widehat\sigma\cdot\vec n))}\), ...where \(\varphi\) is angle of rotation around the axis \(\vec{n}\). But this operator turns the spin in inverse direction presenting the rotation to the left. The error of defining of \(\widehat{U}_{\vec n}(\varphi)\) action is caused because the spin supposed as simple vector which is independent from \(\widehat\sigma\)-operator a priori. In this work it is shown that each fermion marked by number \(i\) has own Pauli-vector \(\widehat\sigma_i\) and both of them change together. If we suppose the global \(\widehat\sigma\)-operator and using the Bloch Sphere approach define for all fermions the common quantization axis \(z\) the spin transformation will be the same: the right hand rotation around the axis \(\vec{n}\) is performed by the operator \(\widehat{U}^+_{\vec n}(\varphi)=\exp{(+i\frac\varphi2(\widehat\sigma\cdot\vec n))}\).
New results of the Delta-Sigma experiment on measuring the
R
dp
ratio made it possible to separate flip and nonflip parts of the differential cross section of the
np
→
pn
reaction at zero angle using ...the Dean formula. Phase-shift-analysis (PSA) solutions for elastic
np
→
np
scattering are transformed into a
np
→
pn
charge-exchange representation using unitary transformations, which testifies to the good agreement of the theoretical and experimental results.
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