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.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with radar
Next generation lens promises more control
Dec 20, 2009 |
4.8 / 5 (22) |
1
(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 ...
Subterranean oceans on Saturn's moon Titan
Space & Earth / Space Exploration
Apr 06, 2009 |
4.3 / 5 (15) |
7
(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, ...
Ghost alps of Antarctica are glimpsed after 14 million years
Space & Earth / Earth Sciences
Jun 03, 2009 |
3.6 / 5 (18) |
2
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.
Engineer creating more sensitive, safer landmine detectors
Oct 30, 2008 |
4.7 / 5 (10) |
1
Long after a conflict, landmines remain buried underground unless someone can locate and detonate them. According to the United Nations (UN), there are more than 100 million landmines buried in 68 countries around the world. ...
NASA Radar Provides First Look Inside Moon's Shadowed Craters
Space & Earth / Space Exploration
Jan 16, 2009 |
4.2 / 5 (10) |
2
(PhysOrg.com) -- Using a NASA radar flying aboard India's Chandrayaan-1 spacecraft, scientists are getting their first look inside the moon's coldest, darkest craters.
Cassini Maps Global Pattern of Titan's Dunes
Space & Earth / Space Exploration
Feb 27, 2009 |
4.9 / 5 (8) |
0
(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 ...
Detecting human activities through barriers
Sep 25, 2008 |
3.2 / 5 (12) |
2
University of Texas professor Hao Ling and Ph.D. candidate, Shobha Ram, are one step closer to making x-ray vision a reality. They are perfecting radar systems that can detect human activities through barriers ...
Triple Asteroid System Triples Observers' Interest
Space & Earth / Space Exploration
Aug 06, 2009 |
4.8 / 5 (8) |
4
(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 ...
ESA map reveals European shipping routes like never before
Space & Earth / Earth Sciences
May 22, 2009 |
4 / 5 (9) |
1
A synoptic view of European shipping routes can be seen for the first time thanks to a new map created using seven years of radar data from ESA's Envisat satellite.
New map hints at Venus's wet, volcanic past (w/ Video)
Space & Earth / Space Exploration
Jul 14, 2009 |
4.1 / 5 (8) |
0
(PhysOrg.com) -- Venus Express has charted the first map of Venus's southern hemisphere at infrared wavelengths. The new map hints that our neighbouring world may once have been more Earth-like, with both, ...
Satellites show how Earth moved during Italy quake
Space & Earth / Earth Sciences
Apr 15, 2009 |
4.6 / 5 (7) |
0
(PhysOrg.com) -- Studying satellite radar data from ESA's Envisat and the Italian Space Agency's COSMO-SkyMed, scientists have begun analysing the movement of Earth during and after the 6.3 earthquake that ...
Satellite data look behind the scenes of deadly earthquake
Space & Earth / Earth Sciences
Oct 15, 2009 |
4.6 / 5 (7) |
0
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 ...
NASA, Japan Release Most Complete Topographic Map of Earth
Space & Earth / Earth Sciences
Jun 30, 2009 |
4.6 / 5 (7) |
1
(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.
Radar Map of Buried Mars Layers Matches Climate Cycles
Space & Earth / Space Exploration
Sep 22, 2009 |
4.3 / 5 (7) |
1
(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 ...
University of Leicester professor adds new perspective to rainforest debate
Oct 17, 2008 |
3.3 / 5 (9) |
6
The Head of Geography at the University of Leicester has addressed an international conference in Brazil on the use of modern radar technology for monitoring the rainforests.
