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Cone Of Silence (radar)
In telecommunications, antenna blind cone (sometimes called a cone of silence or antenna blind spot) is the volume of space, usually approximately conical with its vertex at the antenna (electronics), antenna, that cannot be scanned by an antenna because of limitations of the antenna radiation pattern and mount. The concept was encountered as early as the 1950s in low-frequency radio range, low-frequency radio ranges, when it was used to determine when an aircraft was directly over a station. As the signal may not completely fade away, the aircraft's position could be confirmed by listening for a station location, or "Z", marker. An Air Route Surveillance Radar (ARSR) is an example of an antenna blind cone. The horizontal radiation pattern of an ARSR antenna is very narrow, and the vertical radiation pattern is fan-shaped, reaching approximately 70° of elevation above the horizontal plane. As the fan antenna is rotated about a vertical axis, it can illuminate targets only if th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blind Cone
Blind often refers to: * The state of blindness, being unable to see * A window blind, a covering for a window Blind may also refer to: Arts, entertainment, and media Films * ''Blind'' (1987 film), a documentary by Frederick Wiseman about the Alabama Institute for Deaf and Blind * ''Blind'' (2007 film), a Dutch drama by Tamar van den Dop * ''Blind'' (2011 film), a South Korean crime thriller * ''Blind'' (2014 film), a Norwegian drama * ''Blind'' (2016 film), an American drama * ''Blind'' (2019 film), an American horror film * ''Blind'' (2023 film), an Indian crime thriller, based on 2011 South Korean film of the same name * ''The Blind'' (film), a 2023 American biographical film about Phil Robertson, directed by Andrew Hyatt Music * Blind (band), Estonian rock group founded in 1994, originally Totally Blind Drunk Drivers * Blind (band), Australian Christian rock group founded in 1999 * Blind (rapper), Italian rapper Albums and EPs * ''Blind'' (Corrosion of Confor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunications
Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of transmission may be divided into communication channels for multiplexing, allowing for a single medium to transmit several concurrent Session (computer science), communication sessions. Long-distance technologies invented during the 20th and 21st centuries generally use electric power, and include the electrical telegraph, telegraph, telephone, television, and radio. Early telecommunication networks used metal wires as the medium for transmitting signals. These networks were used for telegraphy and telephony for many decades. In the first decade of the 20th century, a revolution in wireless communication began with breakthroughs including those made in radio communications by Guglielmo Marconi, who won the 1909 Nobel Prize in Physics. Othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antenna (electronics)
In radio-frequency engineering, an antenna (American English) or aerial (British English) is an electronic device that converts an alternating current, alternating electric current into radio waves (transmitting), or radio waves into an electric current (receiving). It is the interface between radio waves Radio propagation, propagating through space and electric currents moving in metal Electrical conductor, conductors, used with a transmitter or receiver (radio), receiver. In transmission (telecommunications), transmission, a radio transmitter supplies an electric current to the antenna's Terminal (electronics), terminals, and the antenna radiates the energy from the current as electromagnetic radiation, electromagnetic waves (radio waves). In receiver (radio), reception, an antenna intercepts some of the power of a radio wave in order to produce an electric current at its terminals, that is applied to a receiver to be amplifier, amplified. Antennas are essential components ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Pattern
In the field of antenna design the term radiation pattern (or antenna pattern or far-field pattern) refers to the ''directional'' (angular) dependence of the strength of the radio waves from the antenna or other source.Constantine A. Balanis: "Antenna Theory, Analysis and Design", John Wiley & Sons, Inc., 2nd ed. 1982 David K Cheng: "Field and Wave Electromagnetics", Addison-Wesley Publishing Company Inc., Edition 2, 1998. Edward C. Jordan & Keith G. Balmain; "Electromagnetic Waves and Radiating Systems" (2nd ed. 1968) Prentice-Hall. Particularly in the fields of fiber optics, lasers, and integrated optics, the term radiation pattern may also be used as a synonym for the near-field pattern or Fresnel pattern.Institute of Electrical and Electronics Engineers, "The IEEE standard dictionary of electrical and electronics terms"; 6th ed. New York, N.Y., Institute of Electrical and Electronics Engineers, c1997. IEEE Std 100-1996. d. Standards Coordinating Committee 10, Terms and D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-frequency Radio Range
The low-frequency radio range, also known as the four-course radio range, LF/MF four-course radio range, A-N radio range, Adcock radio range, or commonly "the range", was the main Radio navigation, navigation system used by aircraft for instrument flight rules, instrument flying in the 1930s and 1940s, until the advent of the VHF omnidirectional range (VOR), beginning in the late 1940s. It was used for en route navigation as well as instrument approaches and Holding (aviation), holds. Based on a network of radio towers which transmitted Radiation pattern, directional radio signals, the radio range defined specific Airway (aviation), airways in the sky. Pilots navigated using low-frequency radio by listening to a stream of automated "A" and "N" Morse codes. For example, they would turn or slip the aircraft to the right when hearing an "N" stream ("dah-dit, dah-dit, ..."), to the left when hearing an "A" stream ("di-dah, di-dah, ..."), and fly straight ahead when these sounds merged ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Route Surveillance Radar
The Air Route Surveillance Radar is a long-range radar system. It is used by the United States Air Force and the Federal Aviation Administration to control airspace within and around the borders of the United States. The ARSR-4 is the FAA's most recent (late 1980s, early 1990s) addition to the "Long Range" series of radars. It is a solid state Westinghouse system with a range. The ARSR-4 features a "look down" capability that enables the radar to detect aircraft attempting to elude detection by flying at low altitudes, advanced clutter reduction via hardware and software post-processing, and enhanced poor-weather object detection. A beacon system, the ATCBI-6M (a monopulse system), is installed along with each ARSR-4. However, since the ARSR-4 has 3D capabilities, it can determine altitude independently of its associated beacon (albeit less accurately). ARSR-4 systems are installed along the borders and coastal areas of the contiguous United States, Guantanamo Bay Naval Ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weather Radar
A weather radar, also called weather surveillance radar (WSR) and Doppler weather radar, is a type of radar used to locate precipitation (meteorology), precipitation, calculate its motion, and estimate its type (rain, snow, hail etc.). Modern weather radars are mostly pulse-Doppler radars, capable of detecting the motion of rain droplets in addition to the intensity of the precipitation. Both types of data can be analyzed to determine the structure of storms and their potential to cause severe weather. During Radar in World War II, World War II, radar operators discovered that weather was causing echoes on their screens, masking potential enemy targets. Techniques were developed to filter them, but scientists began to study the phenomenon. Soon after the war, military surplus, surplus radars were used to detect precipitation. Since then, weather radar has evolved and is used by national weather services, research departments in universities, and in television stations' weather d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NEXRAD
NEXRAD or Nexrad (Next-Generation Radar) is a network of 159 high-resolution S-band pulse-Doppler radar, Doppler weather radars operated by the National Weather Service (NWS), an agency of the National Oceanic and Atmospheric Administration (NOAA) within the United States Department of Commerce, the Federal Aviation Administration (FAA) within the United States Department of Transportation, Department of Transportation, and the United States Air Force, U.S. Air Force within the United States Department of Defense, Department of Defense. Its technical name is WSR-88D (''Weather Surveillance Radar, 1988, Doppler''). NEXRAD detects precipitation (meteorology), precipitation and Earth's atmosphere, atmospheric movement or wind. It returns data which when processed can be displayed in a mosaic map which shows patterns of precipitation and its movement. The radar system operates in two basic modes, selectable by the operator – a slow-scanning ''clear-air mode'' for analyzing air moveme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antennas
In radio-frequency engineering, an antenna (American English) or aerial (British English) is an electronic device that converts an alternating electric current into radio waves (transmitting), or radio waves into an electric current (receiving). It is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. In transmission, a radio transmitter supplies an electric current to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna intercepts some of the power of a radio wave in order to produce an electric current at its terminals, that is applied to a receiver to be amplified. Antennas are essential components of all radio equipment. An antenna is an array of conductor segments ( elements), electrically connected to the receiver or transmitter. Antennas can be designed to transmit and receive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
