Related topics: nasa

Testing mini-radar to peer inside asteroid

A specially upgraded radio-frequency chamber in ESA's technical heart is testing what is set to become the smallest radar system to be flown in space, hosted aboard a breadbox-sized spacecraft.

Titan's river maps may advise Dragonfly's sedimental journey

With future space exploration in mind, a Cornell-led team of astronomers has published the final maps of Titan's liquid methane rivers and tributaries—as seen by NASA's late Cassini mission—so that may help provide context ...

Moon's Tycho crater revealed in intricate detail

The National Science Foundation's Green Bank Observatory (GBO) and National Radio Astronomy Observatory (NRAO), and Raytheon Intelligence & Space (RI&S) have released a new high-resolution image of the moon, the highest-ever ...

Is Venus volcanically active? New approach could provide an answer

Out of all planets in the solar system, Venus has the most volcanoes. Much of the planet is covered in volcanic deposits that are less than 300 million years old, and volcanic activity has played a pivotal role in its history. ...

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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