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
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News tagged with radar
Next generation lens promises more control
Dec 20, 2009 |
4.8 / 5 (22) |
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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 ...
NASA, Japan Release Most Complete Topographic Map of Earth
Space & Earth / Earth Sciences
Jun 30, 2009 |
4.6 / 5 (7) |
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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.
Subterranean oceans on Saturn's moon Titan
Space & Earth / Space Exploration
Apr 06, 2009 |
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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, ...
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 ...
Smarter cars are gaining traction (w/ Video)
Dec 21, 2009 |
5 / 5 (2) |
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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.
Researchers patent enabling technology for spread-spectrum systems
Nov 17, 2009 |
4 / 5 (2) |
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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.
Satellite data look behind the scenes of deadly earthquake
Space & Earth / Earth Sciences
Oct 15, 2009 |
4.6 / 5 (7) |
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Using satellite radar data and GPS measurements, Chinese researchers have explained the exceptional geological events leading to the 2008 Wenchuan Earthquake that killed nearly 90 000 people in China's Sichuan ...
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 ...
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 ...
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.
Triple Asteroid System Triples Observers' Interest
Space & Earth / Space Exploration
Aug 06, 2009 |
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(PhysOrg.com) -- Radar imaging at NASA's Goldstone Solar System Radar on June 12 and 14, 2009, revealed that near-Earth asteroid 1994 CC is a triple system. Asteroid 1994 CC encountered Earth within 2.52 million ...
Boston airport testing radar to avoid avian accidents
Jul 14, 2009 |
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Airports have grappled with the issue of sharing the sky with members of the avian family for decades. Most recently, US Airways Flight 1549 was forced to make a water landing in the Hudson River off of New ...
