Related topics: nasa

Scientists develop filter to suppress radio interference

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 ...

Using weather radar to monitor insects

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.

Cassini explores ring-like formations around Titan's lakes

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 ...

New study reports sea level rise in the Arctic

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 ...

NASA maps surface changes from California quakes

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, ...

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Radar

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.

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