Sudden frequency shift observed at high frequency during ionospheric disturbances

1962 ◽  
Vol 67 (6) ◽  
pp. 2573-2580 ◽  
Author(s):  
L. C. Edwards ◽  
G. D. Thome
Keyword(s):  
Frequency Shift ◽  
High Frequency ◽  
Ionospheric Disturbances

Methods for improving the accuracy of frequency shift estimation in 5G NR

2021 ◽  
Author(s):  
Vladimir Sergeevich Milyutin ◽  
Eugeniy Vasilevich Rogozhnikov ◽  
Kirill Petrovskiy ◽  
Dmitriy Pokamestov ◽  
Edgar Dmitriyev ◽  
...  
Keyword(s):  
Frequency Shift ◽  
High Frequency ◽  
Communication Systems ◽  
Wide Frequency Range ◽  
Wireless Communication Systems ◽  
Frequency Synchronization ◽  
Frequency Range ◽  
Transmission Rates ◽  
Synchronization Accuracy ◽  
High Order Modulation

Abstract Frequency synchronization is a necessary operation for all wireless communication systems. Due to the wide frequency range defined for 5G NR systems, this procedure becomes critical. To ensure high transmission rates and the use of high-order modulation, up to 256 QAM for 5G communication systems, it is necessary to ensure high frequency synchronization accuracy. In this article, we have reviewed various approaches to implementing frequency synchronization and proposed, in our opinion, the most effective method for correcting the frequency shift of the signal.

scholarly journals Simulated high frequency ray paths considering traveling ionospheric disturbances

2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Mariano Fagre ◽  
Bruno S. Zossi ◽  
Jaroslav Chum ◽  
Ana G. Elias
Keyword(s):  
High Frequency ◽  
Ionospheric Disturbances ◽  
Traveling Ionospheric Disturbances ◽  
Ray Paths

Darstellung und Schwingungsspektren von Alkyl-und Rhodanohydrohexaboraten / Preparation and Vibrational Spectra of Alkyl and Rhodano Hydrohexaborates

1988 ◽  
Vol 43 (10) ◽  
pp. 1327-1331 ◽  
Author(s):  
A Heinrich ◽  
W Preetz
Keyword(s):  
Frequency Shift ◽  
Raman Spectra ◽  
Organic Solvents ◽  
Vibrational Spectra ◽  
High Frequency ◽  
Acidity Constants ◽  
High Frequency Shift ◽  
Basic Solutions ◽  
Stretching Vibrations ◽  
Ir And Raman

Treatment of B6H62- with iodoalkanes and (SCN)2 in organic solvents affords the monosubstituted protonated hexaborates RB6H6-, R = CH3, C2H5< C3H7, C4H9, C8H17 and SCN, respectively. The acidity constants of these weak Brönsted acids range for the alkylated species from 8.8 to 9.6, and for R = SCN the pka value is ~5. From basic solutions the salts Cs2RB6H5 can be precipitated, which show band patterns in the IR and Raman spectra typical for monosubstituted hydrohexaborates. The protonated compounds RB6H6- are distinguished from the corresponding Brönsted bases RB6H52- by a high frequency shift of the BH stretching vibrations in the order of 100 cm-1. For Cs2(SCN)B6H5, S coordination of SCN- is supposed because of the high frequency of νCN: 2144 cm-1.

scholarly journals Traveling ionospheric disturbances triggered by the 2009 North Korean underground nuclear explosion

2015 ◽  
Vol 33 (1) ◽  
pp. 137-142 ◽  
Author(s):  
X. Zhang ◽  
L. Tang
Keyword(s):  
Acoustic Waves ◽  
High Frequency ◽  
Ionospheric Disturbance ◽  
Low Frequency ◽  
Ionospheric Disturbances ◽  
Underground Nuclear Explosion ◽  
Dual Frequency ◽  
International Gnss Service ◽  
Acoustic Gravity Waves ◽  
Traveling Ionospheric Disturbances

Abstract. Underground nuclear explosions (UNEs) can induce acoustic-gravity waves, which disturb the ionosphere and initiate traveling ionospheric disturbances (TIDs). In this paper, we employ a multi-step and multi-order numerical difference method with dual-frequency GPS data to detect ionospheric disturbances triggered by the North Korean UNE on 25 May 2009. Several International GNSS Service (IGS) stations with different distances (400 to 1200 km) from the epicenter were chosen for the experiment. The results show that there are two types of disturbances in the ionospheric disturbance series: high-frequency TIDs with periods of approximately 1 to 2 min and low-frequency waves with period spectrums of 2 to 5 min. The observed TIDs are situated around the epicenter of the UNE, and show similar features, indicating the origin of the observed disturbances is the UNE event. According to the amplitudes, periods and average propagation velocities, the high-frequency and low-frequency TIDs can be attributed to the acoustic waves in the lower ionosphere and higher ionosphere, respectively.

scholarly journals Комбинационное рассеяние света в эвтектическом композите InSb-MnSb

2020 ◽  
Vol 54 (4) ◽  
pp. 341
Author(s):  
И.Х. Мамедов ◽  
Д.Г. Араслы ◽  
Р.Н. Рагимов ◽  
А.А. Халилова
Keyword(s):  
Thin Films ◽  
Frequency Shift ◽  
Raman Spectra ◽  
High Frequency ◽  
Theoretical Data ◽  
Eutectic Composite ◽  
Flash Evaporation ◽  
Evaporation Method ◽  
The Matrix ◽  
High Frequency Shift

Raman spectra of bulk samples of the InSb-MnSb eutectic composite and their thin films prepared by the flash evaporation method have been studied. In the Raman spectra observed TO and LO modes at frequencies of 179.5 cm-1 and 192.4 cm-1 correspond to InSb compound and also the peaks at frequencies 122 cm-1, 127 cm-1, 167 cm-1, 211 cm-1, 245.5 cm-1 correspond to theoretical data for MnSb as is well known from literature. The TO mode in the Raman spectra for films is shifted toward lower energies (178 cm-1), but the LO mode is higher (196 cm-1). The high-frequency shift of the LO mode in the composite with compared its value for InSb is probably due to the presence of deformation at the matrix-inclusion interface, as well as the contribution by surface phonons scattering.

An analysis of the profile of the pressure-induced pure rotational spectrum of hydrogen gas

1969 ◽  
Vol 47 (1) ◽  
pp. 65-70 ◽  
Author(s):  
John W. Mactaggart ◽  
James L. Hunt
Keyword(s):  
Absorption Band ◽  
Frequency Shift ◽  
Line Profile ◽  
Power Law ◽  
Infrared Absorption ◽  
High Frequency ◽  
Frequency Region ◽  
Hydrogen Gas ◽  
Rotational Spectrum ◽  
Infrared Absorption Band

The pure rotational infrared absorption band of hydrogen has been investigated in the frequency region 500 to 1400 cm−1. Measurements have been made at densities of up to 100 amagat units and at temperatures of 298, 195, and 77 °K. A blue frequency shift, similar to the shift of the S(0) line observed by Bosomworth and Gush, of the S(1) line of 8 ± 3 cm−1 has been observed. An analysis of the profile has resulted in an individual S line profile which represents the high-frequency wing of the line by a "power law" rather than an exponential shape as presented previously by Bosomworth and Gush.

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