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
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 ...
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 ...
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 ...
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.
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.
Measuring distances in microseconds
Nov 05, 2009 |
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(PhysOrg.com) -- Standard laser devices are fast enough for measuring the size of a room, but they need to be faster for outdoor mobile applications. Researchers have brought these scanners up to speed -- ...
Study uses satellite imagery to identify active magma systems in East Africa's Rift Valley
Space & Earth / Earth Sciences
Nov 04, 2009 |
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A team from the University of Miami, University of El Paso and University of Rochester have employed Interferometric Synthetic Aperture Radar (InSAR) images compiled over a decade to study volcanic activity ...
NRL sensor provides critical space weather observations
Space & Earth / Space Exploration
Nov 03, 2009 |
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Launched from Vandenberg Air Force Base, Calif., aboard an United Launch Alliance Atlas V launch vehicle, Oct. 18, 2009, the Special Sensor Ultraviolet Limb Imager (SSULI) developed by NRL's Space Science ...
Satellite data look behind the scenes of deadly earthquake
Space & Earth / Earth Sciences
Oct 15, 2009 |
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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 ...
Space Radar Reveals Topography of Tsunami Site
Space & Earth / Earth Sciences
Oct 02, 2009 |
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(PhysOrg.com) -- Two color-coded perspective views of the Independent State of Samoa (left) and American Samoa (right), generated with digital elevation data from the Shuttle Radar Topography Mission, illustrate ...
Rensselaer researchers to develop and test next-generation radar systems
Sep 30, 2009 |
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Researchers at Rensselaer Polytechnic Institute have received a grant for $792,000 from the U.S. Air Force to create a new laboratory for developing and testing next-generation radar systems that overcome ...
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 ...
NASA's TRMM satellite sees heavy rainfall in Choi-Wan
Space & Earth / Earth Sciences
Sep 17, 2009 |
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NASA and the Japanese Space Agency's Tropical Rainfall Measuring Mission (TRMM) satellite flew over the center of Super Typhoon Choi-Wan at 2:34 EDT on September 17, 2009 and captured heavy rainfall around ...
Tornado threat increases as Gulf hurricanes get larger (w/ Video)
Space & Earth / Earth Sciences
Sep 08, 2009 |
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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 ...
