Results 21 to 30 of about 1,756 (218)

A Method for Automatic Inversion of Oblique Ionograms

Remote Sensing, 2022
In this study, a method is proposed to carry out automatic inversion of oblique ionograms to extract the parameters and electron density profile of the ionosphere. The proposed method adopts the quasi-parabolic segments (QPS) model to represent the ionosphere. Firstly, numerous candidate electron density profiles and corresponding vertical traces were,
Chunhua Jiang, Cong Zhao, Xuhui Zhang, Tongxin Liu, Ziwei Chen, Guobin Yang, Zhengyu Zhao 0002   +6 more
openaire   +2 more sources

Multi-Station and Multi-Instrument Observations of F-Region Irregularities in the Taiwan–Philippines Sector

Remote Sensing, 2022
In this study, a multi-station and multi-instrument system, organized and proposed for ionospheric scintillation and equatorial spread-F (ESF) specification and their associated motions in the Taiwan–Philippines sector, is outlined. The issues related to
Lung-Chih Tsai, Shin-Yi Su, Jun-Xian Lv, Terry Bullett, Chao-Han Liu   +4 more
doaj   +1 more source

ARTIST ionogram autoscaling confidence scores:best practices

, 2022
Ionogram data from the Global Ionospheric Radio Observatory (GIRO), processed with Automatic Real-Time Ionogram Scaler With True Height (ARTIST), is provided with confidence scores to guide users on the reliability of the data set.
Themens, David; id_orcid, Reid, Benjamin; id_orcid, Elvidge, Sean; id_orcid   +2 more
core   +1 more source

A new algorithm for high‐quality ionogram generation and analysis [PDF]

, 2002
Standard digital ionograms that are generated by fast Fourier transform or autoregressive modeling suffer from high interference levels due to other users of the HF channel which produce artifacts and distortion, hence complicating automatic processing ...
Arıkan, Orhan, Orhan Arıkan, Salous, S, Arikan, F., Feza Arıkan, Arikan, F, Sana Salous, Arıkan, F., Arikan, O., Salous, S., Arikan, FEZA, Arikan, O   +11 more
core   +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   +4 more sources

Unusual Enhancements of NmF2 in Anyang Ionosonde Data [PDF]

Journal of Astronomy and Space Sciences, 2013
Sudden enhancements of daytime NmF2 appeared in Anyang ionosonde data during summer seasons in 2006-2007. In order to investigate the causes of this unusual enhancement, we compared Anyang NmF2’s with the total electron contents (GPS TECs) observed at ...
Jongyeon Yun, Yong Ha Kim, Yong Ha Kim, Young-Sil Kwak, Sunhak Hong   +4 more
doaj   +1 more source

Latitudinal Differences in Spread F Characteristics at Asian Longitude Sector during the Descending Phase of the 24th Solar Cycle

Universe, 2022
By using ionosonde data recorded at Chiang Mai (18.8° N, 98.9° E, magnetic latitude is 9.1° N), Puer (22.7° N, 101.1° E, magnetic latitude is 12.9° N), and Leshan (29.6° N, 103.7° E, magnetic latitude is 19.8° N), the statistical features of different ...
Ting Lan, Chunhua Jiang, Guobin Yang, Fei Sun, Zhenyun Xu, Zhong Liu   +5 more
doaj   +1 more source

Numerical synthesis of ionograms in horizontally inhomogeneous ionosphere on the basis of compound parabolic layer model

Solar-Terrestrial Physics, 2016
Characteristic U-shaped traces (cusps) on ionograms have been identified as off-angle echoes from sloping electron density contours caused by the presence of traveling ionospheric disturbances (TIDs).
Laryunin O.A.
doaj   +1 more source

Anomalous Ionogram Traces over European Mid-Latitudes: Climatology and Association with Travelling Ionospheric Disturbances

Atmosphere
Anomalous ionogram traces are characteristic ionogram signatures, appearing as split, branching, cusp, U-, sickle-, and crescent-shaped structures in the F-region trace, that are commonly associated with travelling ionospheric disturbances (TIDs) and TID-
Blessy Varghese, Krishnendu Sekhar Paul, Ankitha Nandakumar, Ola Abu Elezz, Haris Haralambous, Tiju Joseph Mathew   +5 more
doaj   +1 more source

Performance Analysis of a Portable Low-Cost SDR-Based Ionosonde

Atmosphere, 2023
This work presents a software-defined radio ionosonde (ISDR) developed at the Abdus Salam International Centre for Theoretical Physics (Italy) and the Institute of Radio Astronomy (Ukraine) and installed at the Ukrainian Antarctic Station in 2017.
Oleksandr Koloskov, Anton Kashcheyev, Oleksandr Bogomaz, Andriy Sopin, Bogdan Gavrylyuk, Andriy Zalizovski   +5 more
doaj   +1 more source