scholarly journals Oliver Heaviside and the Heaviside layer

Author(s):  
Hugh Griffiths

In an entry in the Encyclopaedia Britannica in 1902, Oliver Heaviside had suggested the existence of a reflecting layer in the upper atmosphere to account for long range beyond line-of-sight radio propagation of the type demonstrated by Guglielmo Marconi in 1901, in the first transatlantic radio transmission. In about 1910, William Eccles proposed the name ‘Heaviside Layer’ for this phenomenon, and the name has subsequently been adopted and used quite widely. This paper describes the basis of Marconi's experiments and various interpretations of the results in the context of Heaviside's wider work. It also describes some later experiments to measure the height of the ionosphere. This article is part of the theme issue ‘Celebrating 125 years of Oliver Heaviside's ‘Electromagnetic Theory’’.

Author(s):  
Paul J. Nahin

A little discussed aspect of Heaviside's work in electromagnetics concerned faster-than-light (FTL) charged particles, precursors to the hypothetical tachyon and his discovery that such motion should produce a characteristic radiation signature (now called Cherenkov radiation ). When Heaviside wrote, the time travel implications of FTL were not known (Einstein was still a teenager), and in this paper some speculations are offered on what Heaviside would have thought of FTL time travel, and of the associated (now classic) time travel paradoxes, including the possibility (or not) of sending information into the past. This article is part of the theme issue ‘Celebrating 125 years of Oliver Heaviside's ‘Electromagnetic Theory’’.


Mekatronika ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 52-62
Author(s):  
Kwai Yang Sak ◽  
Ahmad Najmuddin Ibrahim

Long Range (LoRa) is a wireless radio frequency technology under the Low Power Wide Area Network (LPWAN). LoRa is able to communicate long range and low energy consumption. The communication range has become an essential element in the wireless radio frequency technology in the Internet of Things (IoT). The presence of LoRa is able IoT application performs in long communication distances with high noise sensitivity ability. People can operate, monitor, and do a variety of tasks from a remote distance. Therefore, this research aims to evaluate the performance of the LoRa connection between radio transceivers in remote locations. The different environment and structural elements affect the LoRa performance. This thesis will be supported by the experiment that LoRa communication in different environments and tests. This experiment tests in line of sight (LOS) and non-line of sight (NLOS). Two sets of LoRa parameters, including Spreading Factor (SF), Bandwidth, and coding rate, are tested in different environments. The experiment tests the LoRa performance in various aspects: received signal strength indicator (RSSI) and packet received ratio (PPR) at different coverage ranges. In addition, the LoRa performance is evaluated in university, residential areas and vegetation areas under similar temperature, weather, and time. The LoRa coverage distance in the vegetation area and university area is reached 900 meters in the LOS test. Still, the vegetation area's signal is more stable and able to receive weaker RSSI signals. The LoRa coverage distance in the NLOS test is shorter compared to the LOS test. NLOS test has only one-third of the LOS LoRa communication distance. It is due to the signal penetration on structural elements such as buildings and woods cause the signal power loss and only transmitting a shorter distance. The LoRa parameter with SF9, 31.25kHz bandwidth and 4/8 coding rate has a better coverage range and stable connection.


2018 ◽  
Vol 6 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Deniss Brodņevs

Abstract Remotely piloted operations of lightweight Unmanned Air Vehicles (UAV) are limited by transmitter power consumption and are always restricted to Line-of-Sight (LOS) distance. The use of mobile cellular network data transfer services (e.g. 3G HSPA and LTE) as well as long-range terrestrial links (e.g. LoraWAN) makes it possible to significantly extend the operation range of the remotely piloted UAV. This paper describes the development of a long-range communication solution for the UAV telemetry system. The proposed solution is based on (but not restricted to) cellular data transfer service and is implemented on Raspberry Pi under Gentoo Linux control. The goal of the project is to develop a flexible system for implementing optimized redundant network solutions for the Non-LOS remote control of the UAV


2012 ◽  
Vol 39 (9) ◽  
pp. 0913003 ◽  
Author(s):  
宋超 Song Chao ◽  
徐智勇 Xu Zhiyong ◽  
汪井源 Wang Jingyuan ◽  
韦毅梅 Wei Yimei

2019 ◽  
Vol 30 ◽  
pp. 05012
Author(s):  
Alexander Generalov ◽  
Elchin Gadzhiev ◽  
Pavel Shmachilin ◽  
Yuri Polushkovskiy ◽  
Vladimir Skripachev ◽  
...  

The ionosphere is the ionized part of Earth's upper atmosphere, from about 60 km to 1,000 km altitude, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth. The region below the ionosphere is called neutral atmosphere, or neutrosphere. In this paper aspects of design antennas for radio occultation method of ionosphere diagnostics are presented.


Author(s):  
Yoshinori Matsuura ◽  
Kohei Shimada ◽  
Yasuhiro Sato ◽  
Masaaki Yamanaka ◽  
Daiki Hashimoto

Author(s):  
V.J. Procopio ◽  
K.H. Brockel ◽  
J.R. Inserra ◽  
F.G. Loso ◽  
P.A. Major ◽  
...  

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