3-D FDTD Modeling of Long-Distance VLF Propagation in the Earth-Ionosphere Waveguide

2021 ◽  
pp. 1-1
Author(s):  
S. Burns ◽  
F. Gasdia ◽  
J. J. Simpson ◽  
R. Marshall
Keyword(s):  
Long Distance ◽  
The Earth ◽  
Vlf Propagation

Basic communication sciences

1969 ◽  
Vol 308 (1493) ◽  
pp. 183-198
Keyword(s):  
Long Distance ◽  
Earth Station ◽  
Early Communication ◽  
Technical Developments ◽  
Radiated Power ◽  
The Earth ◽  
Distance Communication ◽  
Quality Of Transmission ◽  
Communication Equipment

The feasibility and utility of long-distance communication via Earth-orbiting satellites has been demonstrated during recent years and it is appropriate therefore to focus attention on the more important scientific studies and technical developments that will be needed if full use is to be made of this valuable mode of communication in the future. The early communication satellites (the Telstar and Relay series) were pioneers in a relatively unknown propagation environment. The satellites themselves were conceptually simple and the communication equipment consisted essentially of a frequency-changing transponder with an r. f. power output of a few watts and a bandwidth some tens of megahertz. Carrier frequencies in the range 2 to 6 GHz were employed; typically either 2 or 6 GHz was used for transmission and 4 GHz for reception at the Earth station. To obtain an adequate signal/noise ratio at the output of the Earth station receiver, frequency modulation was employed, the frequency deviations being greater than those used on terrestrial microwave links. Launcher limitations and other factors meant that the satellites had to be placed in inclined elliptical orbits (see figure 1) with maximum heights of only a few thousand miles. Nevertheless, these satellites demonstrated that some hundreds of frequency-division multiplex telephony circuits, or a television channel, could be achieved with generally satisfactory quality of transmission. It is to be noted, however, that the satellite transponders accommodated only one, or at the most two, r. f. carriers at any time, and that the transmission performance was at times marginal due to limitations of the satellite effective radiated power. Furthermore, these relatively low orbit satellites provided communication in periods of generally less than an hour at a time and required continuous tracking by the Earth station aerials, due to movement of the satellites relative to the Earth.

scholarly journals Long-period changes of the air temperature in Tatarstan and their forecast till the end of the 21st century

2019 ◽  
pp. 94-107
Author(s):  
Yuri P. Perevedentsev ◽  
Konstantin M. Shantalinskii ◽  
Boris G. Sherstukov ◽  
Alexander A. Nikolaev
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
21St Century ◽  
Ocean Surface ◽  
The Arctic ◽  
Long Distance ◽  
Climate Fluctuations ◽  
Long Period ◽  
The Earth

Long-term changes in air temperature on the territory of the Republic of Tatarstan in the 20th–21st centuries are considered. The periods of unambiguous changes in the surface air temperature are determined. It is established that the average winter temperature from the 1970s to 2017, increased in the Kazan region by more than 3 °C and the average summer temperature increased by about 2 °C over the same period. The contribution of global scale processes to the variability of the temperature of the Kazan region is shown: it was 37 % in winter, 23 % in summer. The correlation analysis of the anomalies of average annual air temperature in Kazan and the series of air temperature anomalies in each node over the continents, as well as the ocean surface temperature in each coordinate node on Earth for 1880 –2017, was performed. Long-distance communications were detected in the temperature field between Kazan and remote regions of the Earth. It is noted that long-period climate fluctuations in Kazan occur synchronously with fluctuations in the high latitudes of Asia and North America, with fluctuations in ocean surface temperature in the Arctic ocean, with fluctuations in air temperature in the Far East, and with fluctuations in ocean surface temperature in the Southern hemisphere in the Indian and Pacific oceans, as well as air temperature in southern Australia. It is suggested that there is a global mechanism that regulates long-term climate fluctuations throughout the Earth in the considered interval of 200 years of observations. According to the CMIP5 project, climatic scenarios were built for Kazan until the end of the 21st century.

scholarly journals World-wide lightning location using VLF propagation in the Earth-ionosphere waveguide

2008 ◽  
Vol 50 (5) ◽  
pp. 40-60 ◽  
Author(s):  
Richard Dowden ◽  
Robert Holzworth ◽  
Craig Rodger ◽  
Janos Lichtenberger ◽  
Neil Thomson ◽  
...  
Keyword(s):  
World Wide ◽  
The Earth ◽  
Vlf Propagation

scholarly journals On Markov Earth Mover's Distance

2014 ◽  
Vol 14 (04) ◽  
pp. 1450016 ◽  
Author(s):  
Jie Wei
Keyword(s):  
Goodness Of Fit ◽  
Empirical Studies ◽  
Earth Mover’S Distance ◽  
Long Distance ◽  
Chi Square ◽  
Earth Mover's Distance ◽  
The Earth ◽  
Order Of Magnitude ◽  
Kolmogorov Smirnov ◽  
System Nodes

In statistics, pattern recognition and signal processing, it is of utmost importance to have an effective and efficient distance to measure the similarity between two distributions and sequences. In statistics this is referred to as goodness-of-fit problem. Two leading goodness of fit methods are chi-square and Kolmogorov–Smirnov distances. The strictly localized nature of these two measures hinders their practical utilities in patterns and signals where the sample size is usually small. In view of this problem Rubner and colleagues developed the earth mover's distance (EMD) to allow for cross-bin moves in evaluating the distance between two patterns, which find a broad spectrum of applications. EMD-L1 was later proposed to reduce the time complexity of EMD from super-cubic by one order of magnitude by exploiting the special L1 metric. EMD-hat was developed to turn the global EMD to a localized one by discarding long-distance earth movements. In this work, we introduce a Markov EMD (MEMD) by treating the source and destination nodes absolutely symmetrically. In MEMD, like hat-EMD, the earth is only moved locally as dictated by the degree d of neighborhood system. Nodes that cannot be matched locally is handled by dummy source and destination nodes. By use of this localized network structure, a greedy algorithm that is linear to the degree d and number of nodes is then developed to evaluate the MEMD. Empirical studies on the use of MEMD on deterministic and statistical synthetic sequences and SIFT-based image retrieval suggested encouraging performances.

scholarly journals ‘They came from the ends of the earth’: long-distance exchange of obsidian in the High Arctic during the Early Holocene

Antiquity ◽  
2019 ◽  
Vol 93 (367) ◽  
pp. 28-44 ◽  
Author(s):  
Vladimir V. Pitulko ◽  
Yaroslav V. Kuzmin ◽  
Michael D. Glascock ◽  
Elena Yu. Pavlova ◽  
Andrei V. Grebennikov
Keyword(s):  
High Arctic ◽  
Early Holocene ◽  
Long Distance ◽  
The Earth ◽  
Image Position

Abstract

scholarly journals Influence of solar X-ray flares on the earth-ionosphere waveguide

2005 ◽  
pp. 29-35 ◽  
Author(s):  
Davorka Grubor ◽  
D. Sulic ◽  
V. Zigman
Keyword(s):  
Signal Amplitude ◽  
Simultaneous Analysis ◽  
X Ray ◽  
Absolute Phase ◽  
The Earth ◽  
Amplitude Data ◽  
Class C ◽  
Vlf Propagation

A simultaneous analysis of solar are X-ray irradiance and VLF signal amplitude on the GQD/22.1 kHz trace was carried out. Solar are data were taken from GOES 12 satellite listings. The VLF amplitude data were recorded by means of the AbsPAL (Absolute Phase and Amplitude Logger) at the Institute of Physics, Belgrade, Serbia. It was found that solar are events from class C to class X affect the VLF signal amplitude in various ways and can be classified according to the type of effect produced in the Earth-ionosphere waveguide on the VLF propagation.

scholarly journals Kecemasan Yang Dialami Tokoh Noboru Terao Ketika Menghadapi Hubungan Jarak Jauh Dalam Novel Hoshi No Koe Karya Waku Oba

2017 ◽  
Vol 6 (1) ◽  
pp. 7-15
Author(s):  
Muhammad Fadhil
Keyword(s):  
Outer Space ◽  
The Novel ◽  
Long Distance ◽  
The Earth ◽  
Long Distance Relationships ◽  
Psychology Literature ◽  
Distance Relationship ◽  
Descriptive Method

ABSTRAK Penelitian ini meneliti kecemasan yang dialami tokoh Noboru Terao dalam novel Hoshi no Koe. Novel tersebut menceritakan tentang sepasang kekasih yang terpisah antara bumi dan luar angkasa. Kedua tokoh utama terpaksa harus menjalani hubungan jarak jauh. Dalam menjalani hubungan jarak jauh kedua tokoh mengalami berbagai macam kecemasan. Dari cerita novel tersebut, penulis tertarik untuk meneliti kecemasan yang dialami tokoh dalam menghadapi hubungan jarak jauh pada novel tersebut. Tokoh utama dalam novel ini ada dua yaitu Noboru Terao dan Mikako Nagamine, namun pada penelitian ini peneliti akan meneliti kecemasan yang dialami tokoh Noboru Terao saja. Penelitian ini akan menggunakan teori kecemasan yang ditemukan oleh Freud. Penelitian ini akan menggunakan metode deskriptif analisis. Objek penelitiannya merupakan kutipan-kutipan yang berkaitan dengan kecemasan yang dialami Noboru Terao ketika menjalani hubungan jarak jauh.  Karena kecemasan merupakan bidang psikologi, penelitian ini akan menggunakan pendekatan psikologi sastra. Dari penelitian ini dapat disimpulkan bahwa dalam novel Hoshi no Koe teraplikasikan teori kecemasan melewati tokoh.   Kata Kunci : kecemasan, psikologi sastra, hoshi no koe     ABSTRACT This research examines the anxiety of the character Noboru Terao in the novel Hoshi no Koe. The Novel tells the story of a separate pair of lovers between the earth and outer space. The two main characters are forced to undergo long-distance relationships. In undergoing a long-distance relationship, both figures experience various kinds of anxiety. From the novel's story, the author is interested in researching the anxiety experienced by the figure in facing a long-distance relationship to the novel. The main characters in the novel are both Noboru Terao and Mikako Nagamine, but in this research researchers will examine the anxiety experienced by the Noboru Terao figure. This study will use the anxiety theory discovered by Freud. This research will use a descriptive method of analysis. The object of the research is a collection related to the anxiety that Noboru Terao experienced when undergoing a long-distance relationship.  Because anxiety is a field of psychology, this study will use a literary psychology approach. From this research can be concluded that in the novel Hoshi No Koe applied the theory of anxiety through the figure.   Keyword : anxiety, psychology literature, hoshi no koe

scholarly journals Erysichthon Goes to Town: James Lasdun’s Modern American  Re-telling of Ovid

2021 ◽  
Author(s):  
◽  
Pippa J. Ström
Keyword(s):  
American Dream ◽  
Environmental Issues ◽  
Long Distance ◽  
Sacred Tree ◽  
Environmental Destruction ◽  
The Past ◽  
The Earth ◽  
The Relationship

<p>The Erysichthon of Ovid’s Metamorphoses is given, in James Lasdun’s re-telling of the story, a repeat performance of chopping down a sacred tree, receiving the punishment of insatiable hunger, selling his daughter, and eating himself. Transgressive greed, impiety, and environmental destruction are elements appearing already amongst the Greek sources of this ancient myth, but Lasdun adds new weight to the environmental issues he brings out of the story, turning Erysichthon into a corrupt property developer. The modern American setting of “Erisychthon” lets the poem’s themes roam a long distance down the roads of selfimprovement, consumption, and future-centredness, which contrast with Greek ideas about moderation, and perfection being located in the past. These themes lead us to the eternally unfulfilled American Dream. Backing up our ideas with other sources from or about America, we discover how well the Erysichthon myth fits some of the prevailing approaches to living in America, which seem to have stemmed from the idea that making the journey there would lead to a better life. We encounter not only the relationship between Ovid and Lasdun’s versions of the story, but between the earth and its human inhabitants, and find that some attitudes can be traced back a long way.</p>

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