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
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 |
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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 ...
Penetrating insights: NIST airframe tests help ensure better shielding for flight instruments
Aug 26, 2009 |
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Airline travelers are used to being instructed to turn off computers and cell phones during takeoffs and landings as a precaution against interfering with the plane’s navigational equipment, but outside sources ...
Ana's path being mapped by NASA Satellites; she's drenching Puerto Rico
Space & Earth / Earth Sciences
Aug 17, 2009 |
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Tropical Depression Ana is currently drenching Puerto Rico, and tropical storm watches are posted for Puerto Rico and the Virgin Islands as Ana continues westward. Both the Aqua and GOES satellites have captured ...
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 ...
New research provides insight into ice sheet behavior
Space & Earth / Earth Sciences
Jul 20, 2009 |
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(PhysOrg.com) -- A new study published this week takes scientists a step further in their quest to understand how Antarctica's vast glaciers will contribute to future sea-level rise. Reporting in the journal ...
Space radar techniques for land mapping
Space & Earth / Earth Sciences
Jul 17, 2009 |
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Entrepreneurs at ESA’s Business Incubation centre in the Netherlands have used radar technology from the agency’s Envisat remote-sensing satellite to develop a compact, high-resolution radar that can monitor ...
