direction finder

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direction finder,

electronic device used to determine the position of a ship or aircraft. In a simple direction finder a radio receiver is equipped with a revolving directional antenna. The antenna receives the strongest radio signal when it is pointing directly at a transmitter. By determining the direction of two land-based transmitters, a navigator may plot his position by triangulation. Direction finders have been replaced in many applications with more accurate systems, such as radarradar,
system or technique for detecting the position, movement, and nature of a remote object by means of radio waves reflected from its surface. Although most radar units use microwave frequencies, the principle of radar is not confined to any particular frequency range.
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 and satellite navigation systems (see satellite, artificialsatellite, artificial,
object constructed by humans and placed in orbit around the earth or other celestial body (see also space probe). The satellite is lifted from the earth's surface by a rocket and, once placed in orbit, maintains its motion without further rocket propulsion.
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Direction Finder


an instrument used in marine and air navigation to determine the direction in degrees to external reference points such as coastal or floating objects, heavenly bodies, and so on.

direction finder

[də′rek·shən ‚fīnd·ər]

direction finder (DF)

A radio receiver equipped with a directional sensing antenna used to take bearings on a radio transmitter. Specialized radio direction finders are used in aircraft as air navigation aids. Others are ground based, primarily to obtain a “fix” on a pilot requesting orientation assistance or to locate downed aircraft. UDFs (ultrahigh frequency direction finders) receive signals in the ultrahigh frequency radio broadcast band; VDFs in the very high frequency band; and UVDFs (UHD/VHD direction finder) in both bands. See automatic direction finder.
References in periodicals archive ?
Under the terms of the agreement, LoJack's time-tested stolen vehicle tracking and recovery software will be incorporated into Becker's search & rescue radio direction finders designed for law enforcement aviation units in the U.
This multichannel direction finder complements the tried and tested Rohde & Schwarz portfolio of networked direction finding and radiolocation systems and is designed for use in especially demanding scenarios.
The new R&S DDF5GTS multichannel direction finder enables fast and comprehensive radio spectrum monitoring, while accurately taking bearings of signals of interest.
Tenders are invited for Provision of Radio Direction Finders.
For those who regularly boat, fish or cruise offshore, the direction finders combined with Personal Locator Beacons (PLBs) become highly effective man-overboard devices that can save your bacon even in the most extreme conditions.
Expert Wiley covers the latest technologies, first defining electronic intelligence and giving its capabilities and limitations and then covering ELINT implications of range equations and radar constraints, characteristics of ELINT interception systems, the probability of intercept, antennas and direction finders, emitter locations, estimation of power at the transmitter, antenna parameters, "low probability of intercept" (LPI) radar and ELINT, antenna scan analysis, intrapulse analysis, pulse repetition interval analysis, deinterleaving pulse trains, measurement and analysis of carrier frequency, determining ELINT parameter limits, and working with ELINT data files.
In addition to codebreaking, B-Dienst operated a network of direction finders that fixed the approximate locations of radio transmissions in the Atlantic.
It seemed to me that Wales had some pretty good direction finders of their own.
The company's receivers, direction finders, antennas, signal analysis solutions and customized systems have made Rohde & Schwarz a reliable partner for homeland and external security for many decades.
They will be equipped with forward-looking infrared and high-resolution digital day/night-vision cameras, satellite communication and navigation systems, digital map devices, Tetra digital radios, collision warning systems, tactical direction finders, digital flight management systems and GSM telephones.
The Lockheed Martin system features a network of remote sensor sites consisting of sophisticated radars, comprehensive camera packages, radio direction finders (RDF) and Automatic Identification Systems (AIS), as well as Doppler current and salinity sensors, surface water measurement and automatic weather stations.
The Friday announcement could spark a booming market in products such as direction finders for cars and hand-held transmitters for lost hikers.

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