Radar
hideRadar is an object detection system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain. The term RADAR was coined in 1941 as an acronym for radio detection and ranging. The term has since entered the English language as a standard word, radar, losing the capitalization. Radar was originally called RDF (Radio Direction Finder, now used as a totally different device) in the United Kingdom.
A radar system has a transmitter that emits microwaves or radio waves. These waves are in phase when emitted, and when they come into contact with an object are scattered in all directions. The signal is thus partly reflected back and it has a slight change of wavelength (and thus frequency) if the target is moving. The receiver is usually, but not always, in the same location as the transmitter. Although the signal returned is usually very weak, the signal can be amplified through use of electronic techniques in the receiver and in the antenna configuration. This enables radar to detect objects at ranges where other emissions, such as sound or visible light, would be too weak to detect. Radar is used in meteorological detection of precipitation, measuring ocean surface waves, air traffic control, police detection of speeding traffic, and by the military.
For more information about Radar, read the full article at
Wikipedia.
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News tagged with radar
Next generation lens promises more control
Dec 20, 2009 |
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(PhysOrg.com) -- Duke University engineers have created a new generation of lens that could greatly improve the capabilities of telecommunications or radar systems to provide a wide field of view and greater ...
Smarter cars are gaining traction (w/ Video)
Dec 21, 2009 |
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(PhysOrg.com) -- Lives can depend on a vehicle's moment-by-moment traction. New European technology promises to make cars as good as experienced, alert drivers at sensing and adjusting to wet, snowy or icy ...
Britain shuts down UFO-hunting unit
Dec 04, 2009 |
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The British government has shut a unit which has investigated UFO sightings for more than 50 years, judging its resources better spent on more earthly threats, it said Friday.
New algorithms for computerized, large-scale surveillance
Dec 02, 2009 |
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A recent AFOSR-funded technology should enable the Air Force to achieve advances in object and target detection technology by using sophisticated algebraic theories called groups, rings and fields.
First phase of pan-tropical forest mapping debuting at COP15
Dec 10, 2009 |
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Tropical forest loss accounts for an estimated 17% of global emissions of carbon dioxide. As part of a strategy to reduce these greenhouse gas fluxes to the atmosphere, the UNFCCC's Conference of the Parties 15 in Copenhagen ...
Researchers patent enabling technology for spread-spectrum systems
Nov 17, 2009 |
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If you've ever gotten the dreaded "network busy" message while trying to make a cell phone call, you've experienced the complication of sharing a single network with numerous other users.
Subterranean oceans on Saturn's moon Titan
Space & Earth / Space Exploration
Apr 06, 2009 |
4.3 / 5 (15) |
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(PhysOrg.com) -- Saturn's largest moon, Titan, may have a subterranean ocean of hydrocarbons and some topsy-turvy topography in which the summits of its mountains lie lower than its average surface elevation, ...
NASA, Japan Release Most Complete Topographic Map of Earth
Space & Earth / Earth Sciences
Jun 30, 2009 |
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(PhysOrg.com) -- NASA and Japan released a new digital topographic map of Earth Monday that covers more of our planet than ever before. The map was produced with detailed measurements from NASA's Terra spacecraft.
Programming tools facilitate use of video game processors for defense needs
Jun 24, 2009 |
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Video gaming computers and video game consoles available today typically contain a graphics processing unit (GPU), which is very efficient at manipulating and displaying computer graphics. However, the unit's ...
Ghost alps of Antarctica are glimpsed after 14 million years
Space & Earth / Earth Sciences
Jun 03, 2009 |
3.6 / 5 (18) |
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Millions of years ago, rivers ran in Antarctica through craggy mountain valleys that were strangely similar to the European Alps of today, Chinese and British scientists reported on Wednesday.
Cassini Maps Global Pattern of Titan's Dunes
Space & Earth / Space Exploration
Feb 27, 2009 |
4.9 / 5 (8) |
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(PhysOrg.com) -- Titan's vast dune fields, which may act like weather vanes to determine general wind direction on Saturn's biggest moon, have been mapped by scientists who compiled four years of radar data ...
Radar Map of Buried Mars Layers Matches Climate Cycles
Space & Earth / Space Exploration
Sep 22, 2009 |
4.3 / 5 (7) |
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(PhysOrg.com) -- New, three-dimensional imaging of Martian north-polar ice layers by a radar instrument on NASA's Mars Reconnaissance Orbiter is consistent with theoretical models of Martian climate swings ...
British UFO sightings spiked when blockbusters released
Aug 17, 2009 |
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Lemon-headed aliens, scrambled fighter jets and mysterious lights over a cemetery were among details of some 800 UFO sightings released by British authorities Monday.
Tornado threat increases as Gulf hurricanes get larger (w/ Video)
Space & Earth / Earth Sciences
Sep 08, 2009 |
2 / 5 (2) |
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Tornadoes that occur from hurricanes moving inland from the Gulf Coast are increasing in frequency, according to researchers at the Georgia Institute of Technology. This increase seems to reflect the increase ...
Chips in official IDs raise privacy fears
Jul 11, 2009 |
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Climbing into his Volvo, outfitted with a Matrics antenna and a Motorola reader he'd bought on eBay for $190, Chris Paget cruised the streets of San Francisco with this objective: To read the identity cards ...
