Results 151 to 160 of about 1,720 (206)

Application of the oblique ionogram as vertical ionogram

Science China Technological Sciences, 2012
The vertical ionogram can provide the important ionospheric parameters, such as critical frequency, virtual height and electron density, for ionospheric research. The oblique ionosonde has the ability to detect the ionosphere over sea and other terrain where it is not practical to deploy vertical sounder and provide more ionograms with less ...
Gang Chen, Chen Zhou, Guobin Yang
exaly   +2 more sources

Estimating the vertical electron density profile from an ionogram: On the passage from true to virtual heights via the target function method

Radio Science, 2012
The paper describes a new simple method of calculation by which an artificial ionogram trace is obtained from a given vertical electron density profile. The method is discussed in terms of the target function method used by Autoscala to output a reliable
Michael Pezzopane, Bruno Zolesi
exaly   +2 more sources

Ionogram generation in HF band by using three dimensional ray tracing

, 2017
In this study, combination of three-dimensional ray tracing and electron density estimator IRI (International Reference Ionosphere) is used to obtain the ionosonde output, ionogram.
Cenk Toker
exaly   +2 more sources

Automatic classification of ionogram with CNN

2020 IEEE International Conference on Consumer Electronics - Taiwan (ICCE-Taiwan), 2020
The ionosphere is an essential part of the near-earth environment. Ionosphere classification, especially the irregularities identification via ionograms in real time has significant meaning in the ionospheric research. In this paper, a method based on CNN is proposed to classify the ionograms automatically.
Wei-Yi Cheng, Ze-Wen Wan, Yi-Di Chen, Zi-Wei Chen   +3 more
openaire   +1 more source

Acquirement and analysis of Doppler ionograms with high accuracy in the ionogram mode from Digisonde 256 [PDF]

Radio Science, 2004
The Doppler frequency shift of the radio echo reflected from the ionosphere is an important characteristic to measure ionospheric movements. Generally, for the Digisonde 256 digital ionosonde, a Doppler frequency shift with high resolution can be obtained in the drift mode. In this mode, the height profile of ionospheric disturbances cannot be acquired
Weixing Wan
exaly   +2 more sources

Ionogram height–time–intensity observations of descending sporadic E layers at mid-latitude

Journal of Atmospheric and Solar-Terrestrial Physics, 2006
A new methodology of ionosonde height–time–intensity (HTI) analysis is introduced which allows the investigation of sporadic E layer (Es) vertical motion and variability.
C Meek, D Pancheva
exaly   +2 more sources

Digital ionogram data

Advances in Space Research, 1990
Abstract This report summarizes the availability of digital ionogram data from the USSR and the French ionosonde stations, and from the Digisonde 256 network. Both manually generated and automatically generated data are discussed.
B.W. Reinisch, A.Ya. Feldstein, H. Sizun
openaire   +1 more source

Automatic Trace Recognition of Ionogram with YOLOv3

2020 IEEE International Conference on Consumer Electronics - Taiwan (ICCE-Taiwan), 2020
The correct trace identification of the ionosphere in ionograms is one of the fundamental steps to the automatic scaling of ionograms. In this paper, a new method based on deep learning network is proposed to identify the traces of ionograms and ionospheric irregularities effectively.
Tai-Yuan Gong, Fan Sang, Tian-Yu Yang, Zi-Wei Chen   +3 more
openaire   +2 more sources

Noise removal in ionograms by neural network

Neural Computing & Applications, 1997
A neural network approach to the extraction of 1hop F-layer traces from oblique-incidence ionograms is shown to offer performance at least comparable with conventional filtering techniques. Preprocessing in the form of background noise and vertical (horizontal) line removal is utilised prior to training a 110∶7∶100 MLP using backpropagation with ...
Markus Hagenbuchner, John Fulcher
openaire   +2 more sources

Infrastructures and Ionograms

2017
This chapter explores how the Alouette satellite’s reorientation of global data flows and mass-production of ionograms altered the natural order at the core of DRTE’s research. The satellite’s unexpected reliability demanded an automated system of data analysis.
openaire   +2 more sources