Results 121 to 130 of about 452,012 (153)

Multi-Position Facility for HF Doppler Sounding of Ionospheric Inhomogeneities in Ukraine

Radio Science, 2021
AbstractThis paper describes a system for multi‐position Doppler ionosphere sounding implemented at the beginning of 2018 in the Kharkiv region of Ukraine, the data processing technique and initial results of data analysis. The system comprises a high frequency (HF) transmitter and three receiving sites making almost a right triangle with catheti of 32.
Oleksandr Koloskov, Evgeny Mishin, Andriy V Zalizovski   +2 more
exaly   +2 more sources

Passive HF Doppler Radar for Oblique-Incidence Ionospheric Sounding

2019 IEEE 2nd Ukraine Conference on Electrical and Computer Engineering (UKRCON), 2019
A multi-path multi-frequency passive HF Doppler radar for oblique-incidence sounding the ionosphere, that has been produced in collaboration between researchers at the Harbin Engineering University and V. N. Karazin Kharkiv National University, is briefly described.
Leonid Chernogor, K P Garmash
exaly   +2 more sources

Vertical Propagation of Coseismic Ionospheric Disturbances Associated With the Foreshock of the Tohoku Earthquake Observed Using HF Doppler Sounding

Journal of Geophysical Research: Space Physics, 2021
AbstractThe vertical propagation of coseismic ionospheric disturbances (CIDs) associated with the foreshock of the Tohoku earthquake was examined using an HF Doppler sounding system. The sounding system used in this study received radio waves at four different frequencies (5.006, 6.055, 8.006, and 9.595 MHz), indicating that ionospheric disturbances ...
Hiroyuki Nakata, Toshiaki Takano
exaly   +2 more sources

Estimation Algorithm of Doppler Shift and Time Delay in HF Channel Sounding

IEEE 2011 10th International Conference on Electronic Measurement & Instruments, 2011
Doppler shift and propagation time delay are important parameters that require measuring in HF channel sounding. For the purpose of exact measurement of Doppler shift and time delay of HF channel, a parameter estimation algorithm is proposed on the basis of digital pulse compression technique, which achieves precise estimation of Doppler shift and ...
Yuzhong Jiang
exaly   +2 more sources

Doppler Frequency Shifts Associated With the 18 September 2022 M6.8 Taitung Earthquake Observed by Local CW-HF Doppler Sounding Systems in Taiwan

Journal of Geophysical Research: Space Physics
Abstract Doppler frequency shifts (DFSs) recorded by local continuous wave‐high frequency (CW‐HF) Doppler sounding systems have been used to study seismo‐traveling ionospheric disturbances (STIDs) triggered by seismic waves of M  ≥ 5.5 earthquakes in the Taiwan vicinity ...
Jaroslav Chum, Jann-Yenq Liu, Jaroslav Urbar   +2 more
exaly   +3 more sources