Results 41 to 50 of about 5,624 (239)
Manual Scaling of Ionograms Measured at Jeju (33.4°N, 126.3°E)
Journal of Astronomy and Space Sciences, 2018 The ionosphere has been monitored by ionosondes for over five decades since the 1960s in Korea. An ionosonde typically produces an ionogram that displays radio echoes in the frequency-range plane.
Yong Ha Kim, Ki-nam Kim
doaj +1 more source
Remote Sensing, 2022 By using fast ionogram observations, we report the first simultaneous observations of ascending ion layers at equatorial and low latitudes. The ionosonde measurements at Sanya (18.3°N, 109.6°E; dip lat. 12.2°N) and Chumphon (10.7°N, 99.4°E; dip lat.
Lianhuan Hu +10 more
doaj +1 more source
Image processing of digital chest ionograms
The British Journal of Radiology, 1988 Abstract A number of image-processing techniques have been applied to a digital ionographic chest image in order to evaluate their possible effects on this type of image. In order to quantify any effect, a simulated lesion was superimposed on the image at a variety of locations representing different types of structural detail ...
J R, Yarwood, B M, Moores
openaire +2 more sources
The effects of crustal magnetic fields and solar EUV flux on ionopause formation at Mars
, 2019 We study the ionopause of Mars using a database of 6,893 ionopause detections obtained over 11 years by the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) experiment.
Chu, F. +7 more
core +1 more source
Ionogram RFI Rejection Using an Autoregressive Interpolation Process
Radio Science, 2019 Defence Science and Technology Group's Digital Oblique Receiving System (DORS) is a direct‐digital high‐frequency ionosonde receiver, capable of collecting high‐quality ionograms simultaneously on multiple oblique ionospheric paths. One of the key signal
M. Turley +2 more
semanticscholar +1 more source
IEEE AccessThe Multi-Carrier Modulation (MCM) technique in the Near Vertical Incidence Skywave (NVIS) propagation mode poses a challenge due to the ionosphere’s dynamic behavior.
Varuliantor Dear +5 more
doaj +1 more source
First LiDAR Observation of Quasi‐Periodic Structures in Mid‐Latitude E‐Region Meteoric Ca+ Layers
Geophysical Research Letters, Volume 53, Issue 5, 16 March 2026.Abstract We report the first LiDAR observations of continuous quasi‐periodic (QP) metal density structures in mid‐latitude E‐region meteoric Ca+ layers using an all‐solid‐state LiDAR system in Beijing (40.4°N, 116.0°E). These QP Ca+ structures, with periods of 2–30 min and vertical wavelengths of ∼2–15 km, were primarily observed above 100 km.
Jixin Guo +9 more
wiley +1 more source
Pengaruh penginapan ke atas disiplin pelajar di Universiti Tun Hussein Onn Malaysia [PDF]
, 2008 Kajian pengaruh penginapan ke atas disiplin pelajar di Universiti Tun Hussein Onn Malaysia (UTHM) ini memfokuskan kepada tiga objektif iaitu mengenal pasti tahap kriteria penginapan dari aspek fizikal dan bukan fizikal yang memberi kesan terhadap ...
Yaacob, Mohd Asmedi
core
Observations of ionospheric disturbances via U-shaped traces on ionograms
Геодинамика и тектонофизика, 2019 The ionospheric vertical sounding is a basic technique for studying the Earth’s ionosphere. Taking into account the fact that conditions for propagation of radio waves depend on the operating frequency, diagnostics of the ionosphere is performed using ...
O. A. Laryunin
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Solar-Terrestrial Physics, 2020 In this paper, we discuss the main types of quasiperiodic variations in amplitudes of a reflected signal during vertical sounding of the ionosphere at middle latitudes.
K.М. Yusupov +7 more
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