Optical fibres are our global nervous system, transporting terabytes of data across the planet in the blink of an eye.
Optics & Photonics
Aug 19, 2019
1
737
Researchers from Siberian Federal University and Kirensky Institute of Physics have proposed a new design for a multimode stripline resonator. The use of such resonators allows scientists to create miniature band-pass filters ...
General Physics
Aug 06, 2019
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9
Scientists are developing a pioneering technique that allows them to monitor insects in the air using weather radars, as part of a research project called BioDAR.
Plants & Animals
Jul 25, 2019
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9
Using observations from the international Cassini spacecraft, scientists have explored the ring-like mounds that wrap around some of the pools found at the poles of Saturn's largest moon, Titan. The study reveals more about ...
Space Exploration
Jul 18, 2019
3
203
Over the past 22 years, sea levels in the Arctic have risen an average of 2.2 millimeters per year. This is the conclusion of a Danish-German research team after evaluating 1.5 billion radar measurements from satellites using ...
Earth Sciences
Jul 16, 2019
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64
Even before Tropical Storm Barry made landfall in Louisiana on Saturday, July 13, it had already dropped a lot of rain on the state. Using satellite data, NASA created a map that shows areas that are likely flooded.
Environment
Jul 15, 2019
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"Robot umpires" have arrived.
Other
Jul 11, 2019
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Damage from two strong earthquakes that rattled Southern California on July 4 and July 5—a magnitude 6.4 and a magnitude 7.1, respectively—can be seen from space. The epicenter of the quakes was near the city of Ridgecrest, ...
Earth Sciences
Jul 10, 2019
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0
China is an example of a country that suffers severe damage caused by high-impact weather and accompanying floods and mudslides. Dual-polarization (dual-pol) radars, first developed in the United States in the late 1970s, ...
Earth Sciences
Jul 08, 2019
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0
A quadcopter drone appears on the radar screen and makes a beeline for the control tower at Paris' Le Bourget airport.
Other
Jun 19, 2019
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11
Radar 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.
This text uses material from Wikipedia, licensed under CC BY-SA
