Results 71 to 80 of about 1,552 (215)

NOIRE-Net–a convolutional neural network for automatic classification and scaling of high-latitude ionograms

Frontiers in Astronomy and Space Sciences
Millions of ionograms are acquired annually to monitor the ionosphere. The accumulated data contain untapped information from a range of locations, multiple solar cycles, and various geomagnetic conditions.
Andreas Kvammen, Juha Vierinen, Juha Vierinen, Devin Huyghebaert, Theresa Rexer, Andres Spicher, Björn Gustavsson, Jens Floberg   +7 more
doaj   +1 more source

Ionogram scaling using Hidden Markov Models [PDF]

2018 26th Signal Processing and Communications Applications Conference (SIU), 2018
In this paper, a novel method for electron density reconstruction using ionosonde data is proposed. Proposed technique uses Hidden Markov Models for extracting echoes that provides valuable information about electron density distribution in order to provide input to a model based optimization technique that reconstructs the electron density ...
Gokhan Gok, Yasar Kemal Alp, Orhan Arikan, Feza Arikan   +3 more
openaire   +2 more sources

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, Tao Yu, Lifang Du, Jin Wang, Xiangxiang Yan, Yan Yu, Wenyu Hao, Yifan Qi, Haoran Zheng, Guotao Yang   +9 more
wiley   +1 more source

A study of the ionogram derived effective scale height around the ionospheric hmF2 [PDF]

, 2006
International audienceThe diurnal, seasonal, and solar activity variations of the ionogram derived scale height around the ionospheric F-layer peak (Hm) are statistically analyzed at Wuhan (114.4° E, 30.6° N) and the yearly variations of Hm are also ...
L. Liu, Liu, L., W. Wan, Wan, W., B. Ning, Ning, B.   +5 more
core   +1 more source

HF radio path modeling by waveguide approach

Solar-Terrestrial Physics
We present a scheme for modeling HF radio signal characteristics along paths of different lengths, which is based on the waveguide approach — the normal mode method.
Ponomarchuk S. N., Kurkin V. I., Ilyin N. V., Penzin M. S.   +3 more
doaj   +1 more source

Study of the Mid‐Latitude Airglow Responses to Geomagnetic Storms Based on Long‐Term Observations in Japan With the TIMED Satellite and Ionosondes

Journal of Geophysical Research: Space Physics, Volume 131, Issue 3, March 2026.
Abstract Variations in nighttime airglow at mid‐latitudes during geomagnetic disturbances reflect the propagation of atmospheric and plasma disturbances from polar heating as well as local chemical processes. However, their detailed mechanisms remain unclear.
Y. Hotta, K. Shiokawa, Y. Otsuka, M. Nishioka, J. Yue   +4 more
wiley   +1 more source

Pemodelan Ionogram Menggunakan Metode Spline Kubik

, 2011
Ionosfer is a part of the earth atmosfer is an influnced layer at radio wave web which is now become an interesting topic at communication system. Some efforts were done by moddeling action from ionosfer layer variability as a time function, location ...
Slamet Syamsudin
core  

Automatic interpretation of oblique sounding ionograms based on hybrid algorithms

Solar-Terrestrial Physics
The paper presents a method of interpreting data on oblique ionosphere sounding (OS) with a continuous chirp signal. Hybrid algorithms for automatic interpretation of ionograms by selected points with significant amplitude obtained during secondary data ...
Ponomarchuk S. N., Grozov V. P.
doaj   +1 more source

Global GNSS Observation of Mesoscale Ionospheric Irregularities (2006–2024)

Journal of Geophysical Research: Space Physics, Volume 131, Issue 3, March 2026.
Abstract Mesoscale ionospheric irregularities are statistically investigated using an unprecedented 19‐year long‐term global GNSS (Global Navigation Satellite System) TEC (total electron content) data set. These irregularities are represented by ionospheric fluctuations within a 5°× ${}^{\circ}\times $ 3.75° ${}^{\circ}$ (latitude by longitude) region ...
Shun‐Rong Zhang, Jing Liu, Anthea J. Coster, Sevag Derghazarian, Philip J. Erickson, Larisa P. Goncharenko, Nestor Aponte, William Rideout   +7 more
wiley   +1 more source

Ray Tracing from an Ionogram

, 1974
203-206A method is presented for ray tracing from electron density information provided by a vertical ionogram. Making use of the same electron density profile shape for true height conversion of the ionogram and for the ray path parameter computation ...
Rao, N. Narayana
core