Results 11 to 20 of about 1,756 (218)

Automatic classification of spread‐F types in ionogram images using support vector machine and convolutional neural network

Earth, Planets and Space
An ionogram image serves as a valuable data for examining the ionospheric bottom side characteristics and variabilities. Spread-F is indicated or identified by plasma irregularity in the ionospheric region.
Phongsachot Benchawattananon, Apirat Siritaratiwat, Pornchai Supnithi, Michi Nishioka, Septi Perwitasari, Puripong Suthisopapan, Anan Kruesubthaworn   +6 more
doaj   +2 more sources

A new inversion algorithm for backscatter ionogram and its experimental validation [PDF]

Annales Geophysicae, 2014
Oblique backscatter sounding is a powerful tool for detecting and monitoring the ionosphere continuously at a remote distance. High-frequency (HF) backscatter ionograms provide the amplitudes of backscatter signals with respect to group path or time ...
J. J. Zhao, C. Zhou, G. B. Yang, C. H. Jiang, S. S. Chang, P. Zhu, X. D. Gu, B. B. Ni, Z. Y. Zhao   +8 more
doaj   +3 more sources

Fast Ionogram Observations of Ascending Thin Layers Locally Transported from the E to F Region at Equatorial and Low Latitudes

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, Guozhu Li, Zonghua Ding, Wenjie Sun, Xiukuan Zhao, Haiyong Xie, Zhengping Zhu, Tatsuhiro Yokoyama, Jiaping Lan, Zhaoguo Huang, Baiqi Ning   +10 more
doaj   +2 more sources

Algorithm for high quality ionograms [PDF]

Electronics Letters, 2000
A new ionogram algorithm, which is highly successful in generating robust and sharp digital ionograms free of artefacts and processing noise, is presented. An important feature of the algorithm is the distortionless zooming capability, which allows the user to concentrate only on the desired magnetoionic components of the ionogram.
Arikan F., Salous, S., Arikan, O.
openaire   +5 more sources

Signature of Y-forking in ionogram traces observed at low-mid latitude Indian station, New Delhi, during the earthquake events of 2020: ionosonde observations [PDF]

Frontiers in Astronomy and Space Sciences, 2023
We have examined ionospheric response to eleven earthquake events measuring less than four on the Richter scale during the year 2020 that occurred in the vicinity of New Delhi (28.6°N, 77.2°E, 42.4°N dip).
Arti Bhardwaj, Arti Bhardwaj, Ankit Gupta, Ankit Gupta, Qadeer Ahmed, Qadeer Ahmed, Anshul Singh, Anshul Singh, Sumedha Gupta, S. Sarkhel, M. V. Sunil Krishna, Duggirala Pallamraju, Tarun Pant, A. K. Upadhayaya   +13 more
doaj   +2 more sources

Direct Observations of Large‐Scale Wave Structure and Post‐Sunset Rise of the Ionosphere in the Generation of Equatorial Spread F

Geophysical Research Letters
Large‐scale wave structure (LSWS) and the post‐sunset rise (PSSR) are two key factors in the generation of equatorial spread F (ESF). In this study, we reported continuous and direct observations of LSWS and PSSR and their effects on seeding ESF by Sanya
Qi Jiang, Jiuhou Lei, Xinan Yue, Fuqing Huang, Rong Xia, Tong Dang, Xiaoli Luan   +6 more
doaj   +2 more sources

A Frequency Selecting Method for High-Frequency Communication Based on Ionospheric Oblique Backscatter Sounding

Remote Sensing
Ionospheric oblique backscatter sounding is an effective means of monitoring the ionosphere which can be used as a frequency selection system to serve HF communication and ensure its quality and stability. But how to obtain effective information from the
Chuqi Cai, Guobin Yang, Tongxin Liu, Chunhua Jiang   +3 more
doaj   +2 more sources

Prediction Result of Next Monochrome Ionogram frame using LSTM-CNN Model

, 2022
Video of next frame ionogram prediction result using simple LSTM-CNN model Paper published in The 9Th International Seminar on Aerospace Science and Technology ISAST ...
Annis Siradj Mardiani, Varuliantor Dear
core   +2 more sources

A comparison of FORMOSAT-3/COSMIC radio occultation and ionosonde measurements in sporadic E detection over mid- and low-latitude regions

Frontiers in Astronomy and Space Sciences, 2023
The investigation of sporadic E or Es layers typically relies on ground-based or satellite data. This study compares the Es layers recorded in ionograms with those detected using GNSS L1 signal-to-noise ratio data from FORMOSAT-3/COSMIC radio occultation
S. Sobhkhiz-Miandehi, S. Sobhkhiz-Miandehi, Y. Yamazaki, C. Arras, C. Arras, D. Themens, D. Themens   +6 more
doaj   +1 more source

INVERSION OF BACKSCATTER IONOGRAMS INTO QUASI-PARABOLIC IONOSPHERIC LAYER PARAMETERS

Solar-Terrestrial Physics, 2020
We present an inversion scheme of the backscatter signal leading edge into parameters of the quasi-parabolic electron density profile, which is based on the comparison of experimental and calculated minimum delays of scattered signals with corresponding ...
S.N. Ponomarchuk, M.S. Penzin
doaj   +1 more source