Misplaced Pages

#552447

26-537: Smart Tag is the former name of a transponder -based electronic toll collection system implemented by the Virginia Department of Transportation (VDOT). It was launched as Fastoll on April 15, 1996. Fastoll was rebranded as Smart Tag in 1998, and was placed under the umbrella of Smart Travel. In November 2007, the Smart Tag brand name was retired in favor of E-ZPass Virginia, several years after

52-422: A communications satellite , a satellite transponder receives signals over a range of uplink frequencies, usually from a satellite ground station ; the transponder amplifies them, and re-transmits them on a different set of downlink frequencies to receivers on Earth, often without changing the content of the received signal or signals. A communications satellite ’s channels are called transponders because each

78-414: A lap they swipe or touch the receiver which is connected to a computer and log their lap time. NASCAR uses transponders and cable loops placed at numerous points around the track to determine the lineup during a caution period. This system replaced a dangerous race back to the start-finish line . Many modern automobiles have keys with transponders hidden inside the plastic head of the key. The user of

104-436: A resident's car with simple transponder is parked in the vicinity, any vehicle can come up to the automated gate, triggering the gate interrogation signal , which may get an acceptable response from the resident's car. Such units properly installed might involve beamforming , unique transponders for each vehicle, or simply obliging vehicles to be stored away from the gate. General aviation General aviation ( GA )

130-520: A result, differences in transponder functionality also might influence the functional description of related optical modules like transceivers and muxponders . Another type of transponder occurs in identification friend or foe (IFF) systems in military aviation and in air traffic control secondary surveillance radar (beacon radar) systems for general aviation and commercial aviation . Primary radar works best with large all-metal aircraft, but not so well on small, composite aircraft. Its range

156-418: A ship's radar screen. Sonar transponders operate under water and are used to measure distance and form the basis of underwater location marking, position tracking and navigation . Electronic toll collection systems such as E-ZPass in the eastern United States use RFID transponders to identify vehicles. Transponders are used in races for lap timing. A cable loop is dug into the race circuit near to

182-567: Is a separate transceiver or repeater . With digital video data compression and multiplexing , several video and audio channels may travel through a single transponder on a single wideband carrier . Original analog video only has one channel per transponder, with subcarriers for audio and automatic transmission identification service ( ATIS ). Non-multiplexed radio stations can also travel in single channel per carrier (SCPC) mode, with multiple carriers (analog or digital) per transponder. This allows each station to transmit directly to

208-640: Is accomplished with light aircraft . The International Civil Aviation Organization (ICAO) defines civil aviation aircraft operations in three categories: General Aviation (GA), Aerial Work (AW) and Commercial Air Transport (CAT). Aerial work operations are separated from general aviation by ICAO by this definition. Aerial work is when an aircraft is used for specialized services such as agriculture, construction, photography, surveying, observation and patrol, search and rescue, and aerial advertisement. However, for statistical purposes ICAO includes aerial work within general aviation, and has proposed officially extending

234-405: Is also limited by terrain and rain or snow and also detects unwanted objects such as automobiles, hills and trees. Furthermore, it cannot always estimate the altitude of an aircraft. Secondary radar overcomes these limitations but it depends on a transponder in the aircraft to respond to interrogations from the ground station to make the plane more visible. Depending on the type of interrogation,

260-560: Is defined by the International Civil Aviation Organization (ICAO) as all civil aviation aircraft operations except for commercial air transport or aerial work, which is defined as specialized aviation services for other purposes. However, for statistical purposes, ICAO uses a definition of general aviation which includes aerial work. General aviation thus represents the " private transport " and recreational components of aviation, most of which

286-412: Is mandatory in controlled airspace in many countries. Some countries have also required, or are moving toward requiring, that all aircraft be equipped with Mode S, even in uncontrolled airspace . However, in the field of general aviation there have been objections to these moves, because of the cost, size, limited benefit to the users in uncontrolled airspace, and, in the case of balloons and gliders ,

SECTION 10

#1732787750553

312-493: Is not limited to: Commercial air transport includes: However, in some countries, air taxi is regarded as being part of GA/AW. Private flights are made in a wide variety of aircraft: light and ultra-light aircraft, sport aircraft , homebuilt aircraft , business aircraft (like private jets ), gliders and helicopters . Flights can be carried out under both visual flight and instrument flight rules, and can use controlled airspace with permission. The majority of

338-655: Is regulated by the Civil Aviation Authority . The main focus is on standards of airworthiness and pilot licensing , and the objective is to promote high standards of safety. General aviation is particularly popular in North America, with over 6,300 airports available for public use by pilots of general aviation aircraft (around 5,200 airports in the U.S. and over 1,000 in Canada ). In comparison, scheduled flights operate from around 560 airports in

364-620: The 21,000 civil aircraft registered in the United Kingdom, 96 percent are engaged in GA operations, and annually the GA fleet accounts for between 1.25 and 1.35 million hours flown. There are 28,000 private pilot licence holders, and 10,000 certified glider pilots . Some of the 19,000 pilots who hold professional licences are also engaged in GA activities. GA operates from more than 1,800 airports and landing sites or aerodromes , ranging in size from large regional airports to farm strips. GA

390-497: The E-ZPass network, and E-ZPass branded transponders operate at all E-ZPass Virginia (formerly Smart Tag) toll collection points. Roads and crossings that accept Smart Tag/E-ZPass Virginia/E-ZPass: Transponder In air navigation or radio frequency identification , a flight transponder is an automated transceiver in an aircraft that emits a coded identifying signal in response to an interrogating received signal. In

416-827: The Smart Tag system became a part of the E-ZPass network. Originally, Smart Tag only operated at certain toll roads and crossings in Virginia. The system became interoperable with the E-ZPass toll collection system on October 27, 2004, although Richmond Metropolitan Authority owned toll roads—Boulevard Bridge, the Downtown Expressway, and the Powhite Parkway (excluding the extension)—did not begin accepting E-ZPass until August 3, 2005; E-ZPass integration had been delayed due to damages from Tropical Storm Gaston . Smart Tag branded transponders operate throughout

442-581: The U.S. According to the U.S. Aircraft Owners and Pilots Association , general aviation provides more than one percent of the United States' GDP , accounting for 1.3 million jobs in professional services and manufacturing . Most countries have a civil aviation authority that oversees all civil aviation , including general aviation, adhering to the standardized codes of the International Civil Aviation Organization (ICAO). Aviation accident rate statistics are necessarily estimates. According to

468-454: The U.S. National Transportation Safety Board , general aviation in the United States (excluding charter) suffered 1.31 fatal accidents for every 100,000 hours of flying in 2005, compared to 0.016 for scheduled airline flights. In Canada, recreational flying accounted for 0.7 fatal accidents for every 1000 aircraft, while air taxi accounted for 1.1 fatal accidents for every 100,000 hours. More experienced GA pilots appear generally safer, although

494-546: The car may not even be aware that the transponder is there, because there are no buttons to press. When a key is inserted into the ignition lock cylinder and turned, the car's computer sends a signal to the transponder. Unless the transponder replies with a valid code, the computer will not allow the engine to be started. Transponder keys have no battery; they are energized by the signal itself. Transponders may also be used by residents to enter their gated communities . However, having more than one transponder causes problems. If

520-539: The definition of general aviation to include aerial work, to reflect common usage. The proposed ICAO classification includes instructional flying as part of general aviation (non-aerial-work). The International Council of Aircraft Owner and Pilot Associations (IAOPA) refers to the category as general aviation/aerial work (GA/AW) to avoid ambiguity. Their definition of general aviation includes: General aviation thus includes both commercial and non-commercial activities. IAOPA's definition of aerial work includes, but

546-466: The power requirements during long flights. Transponders are used on some military aircraft to ensure ground personnel can verify the functionality of a missile’s flight termination system prior to launch. Such radar-enhancing transponders are needed as the enclosed weapon bays on modern aircraft interfere with prelaunch, flight termination system verification performed by range safety personnel during training test launches. The transponders re-radiate

SECTION 20

#1732787750553

572-530: The satellite, rather than paying for a whole transponder, or using landlines to send it to an earth station for multiplexing with other stations. In fiber-optic communications , a transponder is the element that sends and receives the optical signal from a fiber . A transponder is typically characterized by its data rate and the maximum distance the signal can travel. The term "transponder" can apply to different items with important functional differences, mentioned across academic and commercial literature: As

598-850: The signals allowing for much longer communication distances. The International Maritime Organization 's International Convention for the Safety of Life at Sea (SOLAS) requires the Automatic Identification System (AIS) to be fitted aboard international voyaging ships with 300 or more  gross tonnage  (GT), and all passenger ships regardless of size. AIS transmitters/receivers are generally called transponders , but they generally transmit autonomously, although coast stations can interrogate class B transponders on smaller vessels for additional information. In addition, navigational aids often have transponders called RACON (radar beacons) designed to make them stand out on

624-436: The start/finish line. Each individual runner or car has an active transponder with a unique ID code. When the individual passes the start/finish line, the lap time and the racing position is shown on the score board. Passive and active RFID systems are used in motor sports , and off-road events such as Enduro and Hare and Hounds racing, the riders have a transponder on their person, normally on their arm. When they complete

650-467: The transponder sends back a transponder code (or "squawk code", Mode A) or altitude information (Mode C) to help air traffic controllers to identify the aircraft and to maintain separation between planes. Another mode called Mode S (Mode Select) is designed to help avoiding over-interrogation of the transponder (having many radars in busy areas) and to allow automatic collision avoidance. Mode S transponders are backward compatible with Modes A and C. Mode S

676-485: The world's air traffic falls into the category of general aviation, and most of the world's airports serve GA exclusively. Flying clubs are considered a part of general aviation. In 2003, the European Aviation Safety Agency was established as the central EU regulator, taking over responsibility for legislating airworthiness and environmental regulation from the national authorities. Of

#552447