The ionosphere is the ionized part of the upper atmosphere of Earth, from about 48 km (30 mi) to 965 km (600 mi) above sea level, 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 Earth. It also affects GPS signals that travel through this layer.
The High-frequency Active Auroral Research Program (HAARP) is a University of Alaska Fairbanks program which researches the ionosphere – the highest, ionized part of Earth's atmosphere.
A geomagnetic storm, also known as a magnetic storm, is a temporary disturbance of the Earth's magnetosphere caused by a solar wind shock wave.
High frequency (HF) is the ITU designation for the range of radio frequency electromagnetic waves between 3 and 30 megahertz (MHz). It is also known as the decameter band or decameter wave as its wavelengths range from one to ten decameters. Frequencies immediately below HF are denoted medium frequency (MF), while the next band of higher frequencies is known as the very high frequency (VHF) band. The HF band is a major part of the shortwave band of frequencies, so communication at these frequencies is often called shortwave radio. Because radio waves in this band can be reflected back to Earth by the ionosphere layer in the atmosphere – a method known as "skip" or "skywave" propagation – these frequencies are suitable for long-distance communication across intercontinental distances and for mountainous terrains which prevent line-of-sight communications. The band is used by international shortwave broadcasting stations (3.95–25.82 MHz), aviation communication, government time stations, weather stations, amateur radio and citizens band services, among other uses.
Alouette 1 is a deactivated Canadian satellite that studied the ionosphere. Launched in 1962, it was Canada's first satellite, and the first satellite constructed by a country other than the Soviet Union or the United States. Canada was the fourth country to operate a satellite, as the British Ariel 1, constructed in the United States by NASA, preceded Alouette 1 by five months. The name "Alouette" came from the French for "skylark" and the French-Canadian folk song of the same name.
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. Understanding the effects of varying conditions on radio propagation has many practical applications, from choosing frequencies for amateur radio communications, international shortwave broadcasters, to designing reliable mobile telephone systems, to radio navigation, to operation of radar systems.
Ronald Newbold Bracewell AO was the Lewis M. Terman Professor of Electrical Engineering of the Space, Telecommunications, and Radioscience Laboratory at Stanford University.
Sir Edward Victor Appleton was an English physicist, Nobel Prize winner (1947) and pioneer in radiophysics. He was awarded the Nobel Prize in Physics "for his investigations of the physics of the upper atmosphere especially for the discovery of the so-called Appleton layer". He studied, and was also employed as a lab technician, at Bradford College from 1909 to 1911.
Professor Alan Burns FREng FIET FBCS FIEEE CEng is a professor in the Computer Science Department at the University of York, England. He has been at the University of York since 1990, and held the post of Head of Department from 1999 until 30 June 2006, when he was succeeded by John McDermid.
Plasma stealth is a proposed process to use ionized gas (plasma) to reduce the radar cross-section (RCS) of an aircraft. Interactions between electromagnetic radiation and ionized gas have been extensively studied for many purposes, including concealing aircraft from radar as stealth technology. Various methods might plausibly be able to form a layer or cloud of plasma around a vehicle to deflect or absorb radar, from simpler electrostatic or radio frequency discharges to more complex laser discharges. It is theoretically possible to reduce RCS in this way, but it may be very difficult to do so in practice. Some Russian missiles e.g. the 3M22 Zircon (SS-N-33) and Kh-47M2 Kinzhal missiles have been reported to make use of plasma stealth.
The Institution of Engineering and Technology (IET) is a multidisciplinary professional engineering institution. The IET was formed in 2006 from two separate institutions: the Institution of Electrical Engineers (IEE), dating back to 1871, and the Institution of Incorporated Engineers (IIE) dating back to 1884. Its worldwide membership is currently in excess of 158,000 in 153 countries. The IET's main offices are in Savoy Place in London, England, and at Michael Faraday House in Stevenage, England.
Ralph Benjamin was a British scientist and electrical engineer.
Umran Savaş İnan is a Turkish scientist at Koç University and Stanford University in the field of geophysics and very low frequency radio science. İnan was the president of Koç University between 2009 and 2021.
The Faraday Medal is a top international medal awarded by the UK Institution of Engineering and Technology (IET). It is part of the IET Achievement Medals collection of awards. The medal is named after the British physicist Michael Faraday, the father of electromagnetism.
Peter Mitchell Grant OBE, FREng, FRSE, FIEE, FIEEE, FHEA, Eurasip Fellow is Senior Honorary Professorial Fellow, former Regius Professor of Engineering and Head of School of Engineering and Electronics at the University of Edinburgh. In 2004 he was awarded the 82nd Faraday Medal by the Institute of Electrical Engineers for his 'outstanding contributions to signal processing'.
The Regius Chair of Engineering is a royal professorship in engineering, established since 1868 in the University of Edinburgh, Scotland. The chair is attached to the University's College of Science and Engineering, based in the King's Buildings in Edinburgh. Appointment to the Regius Chair is by Royal Warrant from the British monarch, on the recommendation of Scotland's First Minister.
Anthony George Constantinides FREng FIET is a professor of signal processing and the founder of the Communications and Signal Processing Group of the Department of Electrical and Electronic Engineering in Imperial College London. He has been actively involved with research in various aspects of digital filter design, digital signal processing, and communications for more than 40 years. Professor Constantinides' research spans a wide range of digital signal processing and communications, both from the theoretical as well as the practical points of view. His recent work has been directed toward the demanding problems arising in Financial signal processing and he now leads the Financial Signal Processing Lab in the EEE department of Imperial College London.
Sir Martin Nicholas Sweeting is the founder and executive chairman of Surrey Satellite Technology Ltd (SSTL). SSTL is a corporate spin-off from the University of Surrey, where Sweeting is a Distinguished Professor who founded and chairs the Surrey Space Centre.
John Edwin Midwinter OBE FRS FREng was a British electrical engineer and professor, who was President of the Institution of Electrical Engineers from 2000 to 2001.
John Robert Mills was a British physicist and scientific expert who played an important role in the development of radar and the defence of Britain in World War II. After the war he continued his career working for various British government research establishments on a variety of projects until his retirement in 1977.
